I respect the OP's opinion and experience base. I have read many other posts. This however has me scratching my head!
When I play something that fights other than a fighter the comparison is usually to fighter. For example I am an unabashed fan of the flawed blade pact warlock.
And now I find that the comparison/metric we use sucks too!
If everything sucks in combat besides paladin, are we sure it is every class's design that is flawed vs. one that particularly good? If we actually engage in resource management, the paladin is less than overpowered in my opinion. They should not have multiple spell slots ready for smite Every combat. In the case of the paladin, they are set up for a different story (to be more likely). They hit the evil priest with all they have--after maybe being outdone (a bit) on the battlefield in previous fights. You know, destiny and all of that.
And if they don't excel here, they get outpaced by fighters and are no better than several others given two attacks max at other times. Everyone wants to shine sometimes.
The point some have made about "boring" is an interesting one. I have found in the recent past that worrying about the numbers only up to a point has made all the difference in having fun for me. In the very old days we had memorable differentiation of characters despite few customization opportunities aside for appearance, personality and story. For Pete's sake we played thieves with a 19 THACO at 5th level! I am starting to get the old thrill back. The character seems pretty fleshed out and keeping them alive is exciting!
I love feats and skills and sometimes multiclassing. I love 5e. But I have recently determined I can play anything with gusto if it is a cool character. A few points of damage more or less is not going to make or break the fun of playing a fighter unless that is my sole focus.
That said, I play war and strategy games too and the whole point is usually finding some kind of numerical advantage. I get it. I embrace it at times.
But the thrill of surviving dungeons and advancing in level is not hampered (for me) by a few points here or there. If someone cannot have fun because they can do a bit more damage with X instead of Y I have to wonder if they always play "novice" difficulty on video games. Get into your fighter! He looks and acts differently than any other fighter our there. He has feuds to settle, treasure to claim, people to rescue and some to kill!
I am not into that Badwrongfun crap. We need as many D&D players as we can get. That means diversity of focus and interest. But the focus on numbers only is going to lead to disappointment sooner rather than later. When we solve the puzzle and find one has a higher DPR or whatever, that's it. Now you can only play the one class tricked out in the one way?
If you want more out of combat options, perhaps there are some other classes you can investigate. A fighter could be a thug criminal and sneak. Still others might be acolytes who have left the order but still have knowledge or religions. Another one might be sage (bizarre!). Another could be a mountain man and have survival skills. Maybe is you use feats be some sort of war chief that inspires the troops...a champion could even have been a wizards apprentice with the sage background and magic initiate. All kinds of crap to explore. Unless we have it down to an equation...when that is solved the thrill might be gone.