A fighter at level 20 can knock you off your feet, smack you 3 times, use action surge and smack you 4 more times, effectively killing most combatants. Yes, level 20 characters are OP. I said up to for a reason. Oh, he gets his action surges back on short rests? I see, that's much worse than lvl 9 spell slots (which you have 1 of, which can be counterspelled) and you get back on a long rest.
I know what you're saying, martial characters feel weak to you in combat and it's a sentiment I can partially agree with, but I'm not playing my current rogue for combat (though I don't find it boring or something), I'm playing him for all the skills and abilities he brings to the group as part of a team.
Besides, giving shove to everyone just makes the wizard stronger, as he doesn't need to waste his entire action on a shove but can instead do it as a bonus action, leaving his action to rain fire from above. A fighter (mid level) would've only use 1/2 or 1/3 of his action to do so.
