Multiple wallets means I have to have [multiple] accounts;
The original creator of Bitcoin, Satoshi Nakamoto, wanted to create a currency for internet use which did not depend on any trusted third parties. Originally all wallets were software programs that you downloaded and ran on a personal computer.
There were no accounts, no exchanges or other businesses that you had to trust with your money. That was deliberate. You can still use Bitcoin like this today.
Over time people and businesses have seen an opportunity to offer services to people who either don't understand the original intent or who want to treat the currency not as a currency but as a speculative asset to be traded. These people have set up custodial accounts and have often described those accounts as wallets. These wallets are not the sort of wallets that the founder of Bitcoin intended.
You don't have to have multiple accounts. You don't have to have any accounts. You can use Bitcoin with no accounts whatsoever. Just download the wallet software of your choice, transfer all your Bitcoin to that wallet and close all your other accounts.