The Deck (well, Linux too) do support low latency codecs like aptX LL and LDAC (which is Sony-only I read?), although according to a post I saw on
reddit, the Deck seems to default to normal-latency modes when gaming currently but there's a way to override that.
The Galaxy Buds are, based on everything I've read, terrible for gaming, and will have full 200-300ms latency on all non-Samsung devices because they use their own version of aptX Adaptive called Samsung Scalable except no one else supports it (maybe can't, don't know, Samsung is often worse than Apple when it comes to proprietary software stuff and it's why I never buy their hardware anymore because it never works with anything else I have the way I want it to). Samsung makes great hardware but terrible software decisions. There is, unfortunately, probably no way to improve the Samsung Buds connection to non-Samsung devices as Scalable also has a hardware component so it's not just codec support that's missing.
From the research I did, if anyone else is curious, it sounds like best case scenario is around 35-60ms but only for wireless sets that have aptX low latency/adaptive and in the case of aptX, having to manually force the mode on the Deck. Sony WF-1000XM4 are probably the lowest-effort low latency option but they're expensive and LDAC isn't quite as good as they claim, and also it's unlikely to improve - but it's supported out of the box and no fuss to make it work ASFAIK. Any wireless buds that support
aptX Adaptive (which is replacing Low Latency) could potentially see improvement with better software support but require (currently) manually forcing the codec when gaming on the Deck. There are, somehow, gaming specific wireless ones from Razor that have a low-latency mode that everyone says works well (below 60ms), the problem is they have Razor build quality which means it may last 4 days, a few weeks, or indefinitely.
I generally avoid earbuds because I don't have much call to use them, but I might splurge on something just generally good that supports aptX adaptive, and hope the codec support on Deck / Linux is refined. Plus, a good pair of wired earbuds is comparatively cheap so it's feasible for me to get both kinds.
Edit: I realize I asked a question and then probably provided more info than anyone I asked would likely have had, I just kept researching after I posted. I just can't NOT research stuff when looking to buy something.