Data is becoming increasing centralized, generally being absorbed by ecosystems surrounding cell phones. If you switch from one to the other, you have to be able to move it with you. If your account gets banned, it's all lost. You can (and really should) be backing up your data on a regular basis. It doesn't matter where your data lives, you should always have a backup of it elsewhere in case the worst happens.
It's not obvious how to back up your date from Google, so here's how you go about it:
First, log into your Google account. If you don't see this page below when you log in, click the circle in the top right corner with your avatar, or first initial in a colored circle if you don't have an avatar. Then click the button marked "Manage your Google Account".
Next, click "Data and Personalization" on the left side bar and scroll down to "Download. delete. or make a plan for your data". Click on "Download your data".
There will be three steps that appear on the next page. Make sure every check box in step 1 is selected. Step 2 has some options that you can pick from:
Finally click "Create export". The "Export progress" box will appear. The text at the bottom will vary depending on which delivery method you chose above. If you don't have much data, hours or days will probably be minutes. If you picked other than "Send download link via email", the data will get sent directly to that other cloud platform and you can quit reading right now.
Otherwise, wait for an email to arrive from Google Takeout stating that the process is complete to continue. It'll look like this:
Click "Download Files" and you'll have to re-enter your password before being presented with a page that looks like this:
Click "Download" and your data will begin downloading to you. It may shock you the amount of data retained by Google that you never considered before, but now you'll get a good look at it. You can even use it to migrate elsewhere if you like.