I have been using Bitcoin for over 10 years and have never used the testnet. Testnet is a tool for developers. Therefore, I recommend all beginners to use the main network right away. You can buy Bitcoin for 20-30 dollars and try transactions on several wallets. The fastest and most convenient wallet in my opinion is Electrum.
It is not only for developers and it is helpful for everyone. For normal Bitcoin users, they can claim testnet bitcoin and explore very basic practice with wallet, addresss, transaction in order to understand how Bitcoin blockchain works, how to use a Bitcoin wallet for storing bitcoin and sending & receiving bitcoin.
It is helpful because it helps them knowing how to do it and avoid mistakes that can cost them bitcoin on main net. Maybe you joined Bitcoin years ago when it was cheap and you did not mind about testnet as well as in the past if you lost bitcoin, it does not cost you too much money. In 2025, Bitcoin price is too high and testnet is surely helpful for people who want to become Bitcoiners.