it can be, and waiting for the lead acid to die is sensible. I had 3 31group AGMs as mentioned, and they all died early thanks to Covid and sitting for too long without proper charging by my marina at the time
So new batteries where in order. To replace the 3 AGMs, I was looking at around $1500CDN all in for 3 more, which would've gave me around 160 actual amp hours of use (you only can use 50% of lead acid), but I bought the 2 LiP04s 100ah from Renogy for under $600Cnd on sale a piece (going now for $419cdn) with NO taxes at that time (they've do charge now though!), and now have 200 actual amp hours of use, although I've never had to go down below 65% with my solar panel, and no hydro as I anchor out the whole summer. Also for you US boaters who are looking at Renogy, their prices in the US are somewhat higher than in Canada, and if you buy in Canada, you also get the great exchange discount as well