The only drawback is that the battery life has gotten worse since I originally bought it. But if I could easily swap that out, I would keep it for another five years.
EDIT: Oh, and the fingerprint scanner on the power button seems to work way more reliably, IMO, than the embedded fingerprint scanners under the touchscreens.
I'm not saying it's trivial (it's not hard, but has a large enough amount of small actions to execute), but it's definitely worth doubling (or more) the phone duration.
The FamousProducer™ of my phone supported it for 3 years. This is terrible. LineageOS allows me to use it now - over 3 years after the end of support. Screw FamousProducer™.
Given that the S10e's battery life is already waning, I'm not sure I want to do that. But yes! If there were a safe way to do so, I would gladly run LOS on the phone for ten years.