Hey @Vention,
Sorry to hear that you had lost control of your main Steam account. That's certainly a pretty devastating blow for any gamer, aside from the issues that's caused with Apex here.
When it comes to unlinking and re-linking different accounts however, you can find all the details about this process here:
https://help.ea.com/en/help/account/unlink-gaming-accounts-from-ea-account/
As you have found, I'm afraid it is not currently possible to link a different account of the same platform (Steam) if your EA Account has already had that type of account linked in the past. If you're using a new Steam account, unfortunately that means you would need to use a new EA Account as well.
I'm not sure what the process is for Steam so it may be worth reaching back out to Steam support to check, however if you're able to recover the original account and update the information to secure it instead of simply deleting it, that would generally be the better option so as to not lose your progress.
We can certainly pass along the feedback on those limitations but that is not something that can be changed at this time, apologies.