2021 trading lessons learned with more returns and less risks

i started my trading methodology in 2021 a little different than previous years. in 2021, i only bought SP500 etf. i find it this is the safest way and has given me more return and less risks. i 2022, i will probably add more etf for HK market as well. since im buying the index etf, i dont see the technical chart or individual company performance anymore because i am already diversified.