Question to people holding allot in their ledger.

Hello. I'm a holder since 2019. I have a ledger on which i store my bitcoin. Now I begin to wonder what will happen if ledger descides to steal my bitcoin. I never had much but now my portfolio is getting bigger. I only have 24 words and no multisig. I am afraid to create a multisig using electrum, because it needs to reenter my 24 words which i will never do. My question is to the people holding allot of btc. Are you using only the 24 words provided from the hardware device and how secure is that? Do you use multisignature? And as a last question. If i enter my 24 words in a trezor hardware wallet will it detect the same balace ? For example Ledger does the unthinkable, and I dont use my ledger, Can I just continue with trezor? ( I never updated the firmware of the ledger device just because of the new "Recovery Ledger" service.) Can you tell me how much btc you are holding using only 24 words?(you don't need to anwer this one but it will be much appriciated)