Any downsides of using UTF8 collation in SQL Server 2019?

We have some columns in the table that could possibly get some non-ANSI characters and we must store them. Before the SQL Server 2019 there was the only 1 option - NVARCHAR data type, however starting with SQL Server 2019 it is possible to use VARCHAR data type with the collations that ends with %_UTF8. I understand that for full compatibility with the size, I'll need to double the VARCHAR columns size, so if it was VARCHAR(20) it will needed to be VARCHAR(40) to cover the case if somebody would insert text where all the 20 characters are non-ANSI, but are there any other downsides of such collation? The data in that column will be ~99.9% with ANSI characters only.