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.
That kind of recommendation seems quite amateurish to me. To avoid failures on the mainnet, beginners should first and foremost familiarize themselves with the wallet features they intend to use. The testnet is the best environment for this purpose. Even experienced users should test their setups on the testnet
especially when dealing with more complex configurations like decay multisig, multy party access control, etc..before deploying them on the mainnet. The wallet's logic could fail, and it's always safer to catch any issues on testnet rather than on mainnet.