I felt it was worthwhile to replace the SLA in my jumpstarter AIO with light/inflator/inverter/etc, if all it did was jumpstart then maybe I'd pause longer to consider it, but I know I can get a decent jump off a 20AH SLA while most of those Li-Ion jump starter packs have ridiculously inflated CCA ratings, like around 10X their true capacity.
On the other hand, if the size or weight of an SLA causes you to keep it in a cold trunk or garage, it's going to perform worse than an appropriately sized Li-Ion pack that was small enough that you stored it in a warmer area.
Anyway I got a 20Ah SLA replacement from Chromebattery for about $40 before a 10% off coupon and free S/H so $36. Can't complain, I top it off after use or every 6 months. Well one minor issue was they included battery terminal screws but they were too short. Since my pack does multiple things, it has more than one battery cable connected, so needed longer screws. I don't recall why my original screws didn't work, maybe one was metric and the other standard.