custodial wallets don't fix this, you are just replacing it with another issue: "if the company is gone, your bitcoin is really gone too". and that is not the only issue, there is a new one too which is "if the company decides to shut YOUR wallet down, your bitcoin is really gone".
this last one may not seem so serious because it hasn't happened to you yet but nowadays with stupid rules that these centralized services are starting to enforce (eg. coins that had a history of being in a coinjoin) you will be a victim sooner or later.
People use custodial wallets put all their capital under hands of third-party companies and governements. Companies can do scam exits, steal capital of all customers.
Governments can submit sanctions, law enforcement requests on companies and force them to lock (custodial) wallets or shut down companies that own those wallet services.
When I joined crypto, I did not know what are custodial and non-custodial wallets. I only knew that I need a bitcoin wallet to store my bitcoin and blockchain.info (now is blockchain.com) wallet is my first bitcoin wallet. 2 years later, I know how bad that wallet is and I decided to move to non-custodial wallets. Began with Bitcoin Core but it requires huge space in disk to sync and RAM as well to sync the wallet. Finally, I chose Electrum wallet to use.