I've considered this before, but the short software support timeframe given by device manufacturers makes this a costly endeavour. I still have a perfectly functional Galaxy Tab S2 9.7, but even the third party ROMs have dropped it. I have a pixel 4a, and although it works beautifully running a supported version of lineage it's very likely that the modem baseband has a significant vulnerability that Google isn't patching. I don't think running banking or crypto wallet software on those devices is any smarter than running it on my daily driver pixel 8.