An idea for you - consider an electric tanked with a drain water heat recovery unit. Even lower energy usage than a tankless, and while you can still run out of hot water the DWHR significantly accelerates the re-heating. The DWHR unit should last basically forever.

This is what I did, been very happy. Total cost wasn't more than $1,600 (DIY). Tankless is a nice idea but was just too complicated to ever pay for itself as a retrofit.

I’ve had tankless and now have a rheem heat pump water heater. The rheem uses far less energy (~60 kWh/mo) then the instant water heater. Lifespan I’m not so sure about. I know depending on the water quality they can have issues. I’ve seen many tank water heaters still working after 30 years with little to no service.

Tankless are smaller and it’s true they won’t run out of hot water so they do have that going for them.