It is **much** easier to murder an LFP bank if you don't have the correct gear and knowledge to care for them properly, build the failsafe protection systems at bothe the cell and pack levels,, constantly monitor, periodically test and balance the cells etc.
If all goes well depending on the use case, especially temperatures and C-rates, yes LFP can last a **very** long time - 3000 cycles barely broken in, and maybe end up cheaper than lead.
But the up-front investment in not just top quality cells but all that infrastructure, maybe 5-10x the cost of a good FLA bank - depends on your local market conditions
makes getting that ROI very risky financially.
The most compelling reason to pay so much more are use cases where the much higher C-rates, both in and out, are required, aka power density.
Or where half the weight and volume - energy density - adds a lot of value, e.g. racing yacht, small camping van. . .