It was stated since 90s that Quicksilver has yet to reach his full potential, and that his speed will grow higher over time, it took him nearly 3 decades to get to that level if you think about it, he was growing rather slowly actually.
But the context is the amp comes from that as well as the fact his mental blocks which limited his speed were removed.
^^^I just never thought Marvel’d pull the trigger on him.
Maybe they took the hint after watching his portrayal on the big screen, though even if that wrre true, like you said, it took them long enough!
So by unstucking himself from time, he literally moves at TIME STOP speed, it takes him 0 seconds to reach from place A to place B.
Superman is fast, but he is nowhere near to this level of speed, plus Superman never moved in stasis fields which literally stops time basically, he merely moved in a slowed down time fields which don't slow down time that much, which is impressive, but not even remotely close to what Pietro did.
Not only that Superman moving in actual decent stasis fields ends up him being unable to do anything, unless someone like Waverider with his time manipulation helping him.
Thats more the level i’m used to seeing QS at, though. Unlike Flash, he runs on muscle power, so for him to be reaching time stop speed, he’s tapping into some psionics (or something). Mental blocks indeed.
Well, except that Quicksilver is old news, who is only hypersonic, he has gotten a few power boosts, the one in form of terrigen, and the other one as already said his natural potential being unlocked over time, plus recent Scarlet Witch and Synapse unlocking Pietro's mental blocks.
Quicksilver can hit lightspeed, FTL/MFTL, unstuck from time, has picosecond reaction feats, and the list of his recent feats go on.
Well, that Quicksilver is gone, he has reached lightspeed, since 2010 or so, and now he is on complete another level.
Also actually, QS doesn't run of muscle power anymore (he does retain those muscle powers, but they don't most of the job anymore), Quicksilver since his Isotope E upgrade has been running on energy based mechanism like Flash, except QS's body utilizes electromagnetic type of it for the job, he even has pulled some Magneto like skills as well.
As for reaching time stop speed, it might seem like an asspull, but it's not technically, if we look at some lore, - it has been already implied that Quicksilver has Space/Time warping capabilities, which was also inherited by Speed as well when Scarlet Witch created Speed and Wiccan with her magic spells giving them the same abilities as she and QS had, but then we also have Wiccan saying that Speed bends space/time for speed, so the mechanism is the same for QS as well, giving they have the exact same powerset (except QS is faster ).