https://offgridsolarguide.com/lead-acid-battery-brands-for-o...
I haven’t known any Lithium-ion batteries yet, so I have no personal figures on them. But what I’ve heard is generally more like “they said 8–10 years but it’s still fine after 12”.
You can get decades our of a proper lead-acid battery, but only if you correctly account for all those factors. Start with batteries that you add water regularly (I'm not sure if this is monthly or yearly). Then make sure you have more than enough so that even in the worst case power outage they finish at 30% charge (meaning most don't get close to 50% discharge - the 30% an educated guess but needs more research for your conditions since this needs to be a rare event, the more often you get the worst case outage the more charge needs to remain after). Finally make sure you have a good chargers - modern "battery tender" (a brand name - there are others) makes a big difference.
Lead-acid has been used in major large installation and have a long history of lasting for 20 years when treated properly.
Lithium batteries are still new enough that we don't have a history. We have educated guesses, but those guesses tend to be conservative. Maybe they will turn out to last just as long or even longer. Only time will tell if they are as good or not. However we also know you can abuse lithium batteries and get much worse life. (the Nissan Leaf is famous for significantly worse capacity at 8 years)