Who said that? That is old 1990s logic.
Most cars worldwide are using 0w20 since 10 years or more.
Just pour in and forget it. Most engine wear occurs at car startup and 0w flows the best at startup n low temps reducing engine wear.
Anyway, no need to go for odd oils like 10wX, absolutely no need.
Stick to standards like 0w20 or 5w30 for best availability of lubes and prices.