The ending of Spider-Man: No Way Home featured Peter Parker making his biggest sacrifice yet when he gave up his own identity. Thanks to Doctor Strange’s help in Spidey’s third MCU solo film, the world no longer remembers Peter Parker. This was quite the punishment to volunteer for - Peter’s entire life disappeared and no one remembers him now, including MJ, Ned, the Avengers, and possibly even his collection of Tony Stark’s technology.
If there’s any silver lining to Peter Parker’s identity being erased from existence, it’s that Peter no longer has to juggle his life as a teenaged kid with his time spent saving the city as Spider-Man.
To further emphasize that fact, Peter showed off a new suit in the closing moments of No Way Home that he sewed together himself, and it seemed… less capable than his recent outfits.
Considering the possibility that Peter may never be able to use Stark Tech the same way again following the events of No Way Home, it makes sense that the wall-crawler had to go back to basics with the classic red-and-blue threads by the end of the film. However, there’s also the chance that Peter Parker made the call for himself that the responsibilities of Spider-Man should fall on the web-slinger himself and not on someone else’s tech upgrades.
As his third MCU film progressed, Peter might have recalled his talk with Tony in Spider-Man: Homecoming and remembered what the Armored Avenger told him when he was just fifteen years old:
“If you’re nothing without this suit, then you shouldn’t have it.”
-Tony Stark, Spider-Man: Homecoming
Take it from the guy who provided the web-slinger with all those sweet tech upgrades over the years.
Stark’s stern talking-to in Spider-Man: Homecoming became a defining line that Peter Parker would carry with him through the movie’s final battle against Vulture and beyond. Tony’s sentiment taught Peter how to truly be a hero, regardless of the cool gadgets and upgrades that he got through his relationship with Iron Man.
It’s easy to forget that Peter was ready to go back to basics at the end of Homecoming, since he had proven that he didn’t need Stark’s toys to be the hero that New York City needed. In fact, Tony even presented Peter with the Iron Spider armor and an open invitation to join the Avengers by the end of the film, both of which Peter declined.
Nevertheless, Stark found ways to continue helping Peter along his hero's journey by supplying the wall-crawler with various upgrades and enhancements; some of those tools and toys proved useful in No Way Home. For example, the Iron Spider nanotechnology helped tremendously by keeping Doc Ock’s mechanical arms locked down.
Even so, Spidey’s third MCU outing also showed that Peter could get the job done without any assistance from Tony Stark’s vast collection of tech. This was shown most prominently when Spider-Man had to turn his latest Stark suit inside-out in No Way Home and wear it with all of its tech and various wires exposed.
Seeing that the inside-out suit seemingly served no greater purpose while the web-head was hunting down the Multiversal villains, it was a great way to show that Peter needed nothing more than his webs and his wit to solve a problem even as big as Electro.
“What if somebody had died tonight? Different story, right? ‘Cause that’s on you.”
-Tony Stark, Spider-Man: Homecoming
Spider-Man choosing to turn towards a more traditional super-suit and ditch the Stark Tech at the end of No Way Home is reflective of Peter’s way of assuming responsibility — something he tried to avoid throughout No Way Home.
Peter spent a great amount of time in his third MCU flick trying to escape his duties, mainly by trying to send the Multiversal villains back home without attempting to cure them of their various conditions. Aunt May’s death only made Peter’s decision to help the villains more difficult, especially since Green Goblin was one of the villains in need of saving while also being the one that killed May.
It wasn’t until Peter met the two other Spider-Men from the Multiverse that he decided to once again take ownership of the mess he created. He did so because they echoed May’s last words to the wall-crawler: “with great power comes great responsibility.”
This was the motivator that Peter needed in order to realize that the responsibility of helping these Multiversal villains fell on his shoulders. That epiphany presented itself to Peter through two Variants of himself from the Multiverse that didn’t need any Stark gadgets or fancy weaponry to carry the responsibilities of Spider-Man.
With that in mind, it probably isn't a coincidence that Peter chose to go back to the classic red-and-blue look that is reminiscent of both Tobey Maguire's and Andrew Garfield's Spider-Men.
Tony Stark once told Peter Parker that he shouldn’t have an upgraded super-suit if he can’t be just as good of a hero without it. And although Peter may still have that Stark Tech stashed away somewhere, those wise words from Stark may end up being one of Peter’s most treasured memories of Iron Man as he now ventures into the unknown.
With nothing more than the threads he sewed together himself at the end of No Way Home, Peter Parker is once again ready to take on the responsibilities of Spider-Man. Ironically, Peter has Tony Stark to thank for his ability to let go of the Stark Tech he once relied so heavily upon.