However your post makes a few assumptions, namely:
- Bounded accuracy is a good thing & only a good thing
- Bounded accuracy allows enough design spacefor characters to grow over the course of a campaign with only roll2d20 keep the higher/lower & double proficiency bonus
- Bounded accuracy as implimented is something that could not possibly be improved with a redesign that adds more designspace for character growth.
Everything you cite as a problem with guidance it's evidence that one or more of those assumptions
must be false because in the very first 5e rulebook titled the Player's Handbook that wotc couldn't even manage to get past cantrips & first level spells like
bane before they ran out of alloted designspace & were forced to start circumventing bounded accuracy. You could argue that the dragonmarked races in Rising are more akin to 3.5 trying to stretch the eventually exhausted system's designspace years in when they released tome of battle book of 9 swords, but that doesn't apply when they have to crash through the ceiling on things gained by first level characters in PHB
People frequently point at the 9th level spell wish available at level 17 as evidence that casters are overpowered & other nonsense even though 90% of campaigns
don't make it past level 10 & less than 5% even reach levels where wish can be cast... oddly though, guidance rarely ever comes up .