No, it's a bad fit. it would be pure marketing. Lipo slowly destroy themselves when charged. Lead acid slowly destroy themselves when not charged.

There are different LIPO chemistries. LFP in particular has little problem with being fully charged. You'll see it get swapped in for lead acid chemistries even in places like car/motorcycle batteries.

If you want an Lithium power supply then the keyword to look for is "LFP".

And LFP is also cheaper per unit energy and less of a fire hazard. Hard to imagine why you would use a different lithium-chemistry in a UPS.

Can't we just not push the lipos to 100% and have the UPS maintain a ~60% charge instead and get a long life span?

Many of these power stations (including the one I linked) are LFP chemistry