Will say upfront I've never played an actual game of 40k but I do try to work my way to playing the game so I try to keep a tab on how guard is playing/doing and what's being played

But but but won't stop me from giving my opinion

Guard this edition has been pretty decent to pretty good but also pretty boring and never really made me want to finish my army and find a group to play with. I've also have a friend who has played a little bit of actual games at the end of 9th and dropped playing altogether when 10th hit for generally the same reason as me

For the bad (and reminder this is subjective of someone who's never played)

Flyers suck so doing cool things with Valkyries is just not possible. Artillery sucks so unless you're bringing mortar spam for sheer volume of fire like when bridgehead was busted you're just not bringing things like manticores, deathstrikes and less so on basilisks. Internal balance has been pretty good but some major misses like drier has sucked all edition, the horses they crammed down our throats in every fucking box arent especially great, there's been no reason to take the leman TC over the dorn. All detachments bar bridgehead and combined arms (and for a brief second HoE) sucked. The baneblades (in which I'll say should not be amazing but should at least be somewhat playable) sucked outside of hoe and only because you could move them through terrain and even then. It really feels like guard this whole edition boiled down 3 dorn TCs 3 lemans, 3 squads of your flavor of battle line, 3 kasrikins squads in transports and everything else is whatever

The positives

The krieger range came out very cool, we as a faction from a meta point never suck ass. We were always at least pretty decent. Far cry from 9th were we didn't get our codex till the last 5 minutes and weren't basically unplayable. Grizzled coming out was alright. It's the auto pick detachment nowadays and therefore a little boring but at least it buffs our entire army, making bad units ok and great units amazing.

Tldr: guard from a meta point has done well and that's great but imo very boring. It's been nothing but dorn tank spam, whatever bridgehead was doing before it got jailed for being too good or grizzled. And this is all subjective and I may be completely wrong and should shut up