Questions about BTC platform Safety

Hi,

First time poster here. Pardon my ignorance. I know almost nothing about bitcoin.

I have a few BTC purchased at coinbase and 0.3 BTC at Fidelity Crypto.

Now that the price has risen quite a bit, its quite a large part of my portfolio.

My question is about risk of Coinbase and Fidelity Platforms and pros and cons. If Bitcoin goes to $5 Million dollars will I actually be able to access this money and use it and retire off of it with these platforms?

I saw a video today linked below talking about how I should get my BTC from Swan and then put it in a cold wallet. That sounds complicated and like theres also other ways this could go wrong.

Please dont tear me apart for ignorance, just looking for some direction of what is the wisest way to protect these assets.

Thanks in advance,

Kevin

https://youtu.be/jNgf4MMw0Do