A high-level crossbow expert sharpshooter has a damage potential of 5d6+15*5 = 90 damage as contrasted to the "default" sword-n-board fighter with 4d8+4*5=30 damage. Even though doesn't take all your tricks into account, it still gives a rough picture of how big the difference can be.
And to be clear: That's WAY too much of a difference. That's MIND-BOGGLING. Contrast the situation where you remove feats from the equation (and specifically the CE/SS feats only).
Now the archer (because crossbows no longer suit high-level characters) has a damage potential of 4d8+4*5=30 damage. The fact she's got much better reach is balanced by the vulnerability to melee (if a monster catches up to her she's disadvantaged in combat).
Even if a greatsword wielder could somehow reach 4d12+4*8=50 damage potential it would still be borderline okay. Sure you gain roughly 50% damage, but you lose the shield bonus and associated defensive boons. The most important such "boon" is you're a melee build. If the monsters can't reach you, you can't deal out all that sweet damage. Suddenly all the retreating, kiting, maneuvering, cover-taking tactics that IMHO fit a modern setting much better lose a large portion of their appeal because, unlike the crossbow sharpshooter, you can only avoid monster melee by also not dishing out fearsome damage. This is a HUGE difference, a true gamechanger (for the better).
I don't know if others have replied to this or not as I haven't read posts past this one. I can't tell if you intentionally butchered the math or not to make ranged look better. But here's the actual correct math:
A hand-crossbow using crossbow expert/sharpshooter shooting five times and using the -5/+10 portion of the feat does a maximum of (1d6+15)*5 =92.5 damage
The featless sword and shield user, who undoubtedly took dueling fighting style, does (1d8+7)*4 = 46 damage, not 30 damage.
The difference is 2x not 3x and the sword/shield guy still has a bonus action and two feats to play with. And we haven't taken hit chance into effect. So let's do so.
The archery style handcrossbow user has +12 to hit reduced to +7 if he uses -5/+10. Against AC18 he'll hit on an 11 or higher, or exactly 50% of the time. The sword/shield user has +10 to attack and hits on an 8 or higher, or 85% of the time. The crossbow user's damage is now reduced to 46.25 and the sword/shield reduced to 29.9.
The bow user's advantage is now only 50%, not 200% like in your example. If a feat boosts damage by 20% like you say one should then taking two feats boosts damage by 44%, not far off from the 50% difference we see.
But we haven't even given the sword/shield guy any feats! So let's give him some. You could give the s/s guy GWM as the bonus attack works with a one-handed sword. It wouldn't be awful if you were a Champion and had four attacks as you'd crit once 35% of the time and you'd probably knock a creature to 0 xp quite often. So, say, you get to use it 60% of the time. Your damage is now 34.4.
Give the s/s guy shield mastery instead. On a turn he knocks an AC 18 opponent prone he hits 87.75% of the time (and if he dipped rogue to get expertise in athletics he has 1d6 sneak attack). His damage (if not dipping rogue) is now 40.37 and the bow user is only 14.5% ahead.
If he dipped rogue he'll almost never miss (.02% with prone advantage or 1.5% without) four times so that extra d6 is basically guaranteed. At this point he does 43.87 and the bow user is only 5.4% ahead.
But you
still have one more feat to go! You could give him defensive duelist or heavy armor master or a non-combat feat or boost his Constitution. Whatever. There aren't too many actual damaging combat feats for a single weapon user. But let's take Savage Attacker (which is really weak). Rerolling any time you get less than average (a 1-4) yields an increase in damage of 2.3. Now your average (assuming no rogue sneak attack) is 42.7 if you can prone someone or 32.2 if you can't.
Alternatively, you could take Sentinel and you'd be adding 7.48 dmg (11.5 dmg x 65% hit chance) every time you got to use it, though I leave it to the reader to figure out how often you'd get to use it a round.
On a good round, a sword/shield using sentinel/shield mastery level one rogue dipping fighter will actually outdamage the crossbow user 48.74 to 46.25. If you are a Battlemaster and you've got a buddy to fight with you can Sentinel/Riposte your way to an extra reaction attack (and sneak attack if you dipped rogue) at a high frequency every round.