You have 2 things decentralized in terms of nodes and decentralized in terms of mining.

For mining:
I thought it was gong to happen when the block rewards dropped down to 6.25 last year but I guess it's not going to happen till 3.125 or 1.5625 when a lot of the larger pools start to shut down. Unless the BTC price goes above $100k USD and stays there it's going to cost more to run big pools then they can generate. So I think a lot of smaller pools will start to pop up. I also think a lot of miners will drop out since it's going to be harder to make money. Once again that's if the price stays where it is, $100k or $200k BTC and all bets are off.

For nodes: Drive's are falling in price, 5g is coming online in a lot of places, starlink and Project Kuiper are going to bring high speed internet to a lot of places. I think once that happens, when you can get a RPi type box with 2 TB of storage you are going to see a lot more project nodes and things come online all over the place.

Just my opinions, I could be wrong :-)

-Dave