1 less tank will make certain heroes be viable to play and it create less visual clutter on the battlefield ( something which i have despised for so long, im happy they addressed it), but there will still be problematic strats and abilities that make overwatch a subjectively annoying experience.
You think doomfist with bubble is annoying? Try 2 bubbles on doomfist. Or 2 bubbles on nanoed blade. There will still be problematic things in the game that will still make me hate this game, 5v5 is i think a helpful step but i hope theres more