yes, theres gonna be comparisons to marvel rivals. i am currently mostly playing rivals, but i still queue up for some ow games every couple of days.
the fundamental difference in how it feels to play rivals and ow is the following for me personally:
in rivals, both burst damage and heal is more present, but also in an equilibrium. assuming you play 2-2-2 or something similiar, it is pretty hard to get a lethal angle on the backline. sometimes theres gonna be a flanker thats overextending for an easy pick. that means that more often than not, the mid fight is mostly poking out cooldowns and gaining an advantage until finally, you can make the push or use some ults to win the fight and gain the advantage. the game feels much more ebb and flow than current 5v5 overwatch.
in ow2, the mid fight is much more lethal. many heroes have tools that can lead to something that cannot be outhealed. ultimates and cooldowns more often than not are unanswered and lead to a pick or 2 immediatly.
for me personally, in an ow2 game i am under constant stress, constant pressure. in rivals, when say the enemy luna ults (its a 12 second transcendence basically), you can disgengage and set up your play. sure theres gonna be moments where i have to land shots and have little margin for error. but for me, rivals doesnt have those sort of hard break points that in ow2 many heroes have.
another interesting point: the map design of both games is actually pretty similiar. both games have a distinct lack of cover and many open spaces/corridors. but as we all know from ow1, thats fine if you have a 2-2-2 composition. in ow2 this further leads to unavoidable deaths and angles you just cant cover properly.
i think overwatch should redesign the maps properly for once, if they stick to a 5v5 format. really think about the pain points of 5v5, what abilities (like ana nade or discord) are still broken and what can be done about it. not only changing the heroes kits but also the games design.
in rivals for example: healthpacks are or atleast feel way more accessable and frequent. and all of them are essentially megas, healing some portion as burst and some as heal over time. i think thats genius.
also: on payload maps/modes, the payload actually moves ever so slightly, even if nobody is on it. but its faster than in ow, if 3 people are on it. another thing that just feels like a more thoughtful solution than in ow (even though i get that this one is personal preference)