About google having our code is just something to also worry but just in case you can't sleep about it, don't store millions to your account. Send them to your personal wallet.
Google Authenticator now allows users to create and download a backup of their codes. Were you able to import this backup into Aegis or did you add the 2FA codes manually? Also, can Aegis be used all over the place same as Google Authenticator or does it come with some limitations? I am considering using Aegis myself, so it might be good to know.
I am almost certain that back then Google Authenticator didn't have any kind of export/backup (I am surprised it has now!); however, I've imported them manually.
I am not sure what you mean by limitations for Aegis. It's an Android (5+) application and I think that's the only platform it was made for (at least until now). So it cannot be used "all over the place". (But that doesn't affect me, really).
The only thing I've missed in Aegis (and it happened only once) was the time sync Google Authenticator used to offer.
I didn't do this 2 years ago and when I lost my phone, I have to submit a ticket to binance and perform the KYC again which they end up wanting me to blink on the camera and the documents needed. It's better to just have it backed up manually and then whenever you lost your phone, you can just scan the code again.