Electricity costs are a big factor in this, imo.

Rates for my northeast town increased by ~25% in 2024 and are going up by another ~10% this year. It's a hard sell to spend a large amount of up-front money (even after rebates, which decreased this year) to convert to a system that will cost you more than you pay today, and may not work as well in cold weather (every heat pump company I talked to suggested keeping my existing gas heating in place and automatically switching to it when it gets cold enough).

I was also told that the electrical grid in my area is having difficulty keeping up with the push towards heat pumps, which increase load exactly on the coldest nights of the year, when you need heating most.