Obviously you can create multiple wallet addresses with one Trezor hardware wallet and just one seed phrase. However, I don't know if one seed phrase has more than one BTC address, if our Trezor hardware wallet has problems such as a dead screen or other problems, other BTC wallet addresses (not the main wallet in Trezor) can be accessed in other BIP39 wallets or not.
In my experience
https://bitcointalk.org/index.php?topic=5467802.0, I have 4 BTC wallet addresses in one trezzor with one seed phrase, because there was a problem with my trezor, I was forced to access it in the BIP39 wallet (I use a trust wallet here) where only my main BTC address appeared.
My advice is that if you want to create other addresses on a single hardware wallet, make sure to also create a phrase for each wallet address. This is done in anticipation as a backup so that the funds we store there can be accessed safely and well in all conditions.
I don't quite get your point, but to make it clear, you can generate as many Bitcoin addresses as you want with your seed phrase. So you don't have to have one hardware wallet for every single Bitcoin address. My golly, you'd end up having a full bag of hardware wallets if you do it that way.
Moreover, most hardware wallets can only support one seed phrase. In which case, you cannot generate a new seed phrase every time you generate a new address. If you want to generate a new seed phrase from a single hardware wallet, you need to reset it, wipe everything off, and start all over again as if the hardware is new.
But is there a need to have one set of seed phrase for every address? That sounds crazy. That's possible, though, but your room will surely be filled with back ups. Imagine, you'll consume tens of addresses, if not hundreds in your entire lifetime, and you need to have at least 3 copies of each seed phrase.