I suspect that it's perfectly valid to name a column "from" or any other SQL keyword so allowing a trailing comma would make the grammar ambiguous.
Personally I agree with the sentiment, I find it annoying to have to juggle the commas on the last column name but I think there is likely a valid reason to do with making lexing easier to reason about.
Most SQL implementations do seem to allow you to name a column or a table with a keyword, but to refer to it you may need to put it in quotes or backticks.
I'm not sure if this is a solved problem at the level of the ANSI SQL spec or if every vendor does their own thing, but there's definitely plenty of precedent that ambiguous grammar is allowed and can be resolved.
I know that MySQL uses backticks, Postgres/Sqlite uses double quotes, and MS SQL Server uses square brackets, when using keywords for a column or table.
Personally I agree with the sentiment, I find it annoying to have to juggle the commas on the last column name but I think there is likely a valid reason to do with making lexing easier to reason about.