It depends on where you live (country).
Many countries have now introduced regulations to protect consumers from losing their money and also to prevent money laundry/criminal activities.
This means that for crypto companies it is more work to set up new users and "watch" what their customers are doing. They are required to follow more rules (like reporting suspicious transactions to the government/authorities) which means it is more expensive to run their business.
Some don't want or can't provide that kind of oversight, so some crypto companies have decided not to offer their services in specific countries.
Be careful and read the terms & conditions!
Some organizations offer that you can BUY crypto through them and keep it in a wallet (same as a bank account), but then they won't allow you to SELL your crypto currency and exchange it back into "normal" currency like GBP or EUR or USD etc to move it back into your traditional bank account.
You don't want to get stuck with a whole lot of crypto currency when the market goes down. You want to be able to pull out quickly without having to set up another account first (which can take a few hours to a few days).