Superboy (a teenage Clark Kent fighting crime in costume in Smallville not the clone), is concept that was wiped away in Crisis on Infinite Earth's. But even 1978, the movies didn't have Clark don the costume until he was in Metropolis.
I do think it works better if Clark is not a costumed hero until adulthood, but that doesn't mean the basic Superboy concept has to go away.
This concept still has some life in it after 1986. There was a Superboy show where Superboy was fighting crime while attending college in Florida.
The biggest example of a modern take on Superboy is Smallville, where teen Clark Kent fights crime subtlety, without a costume. It lasted for 10 years. Clark still wants to help people, but has not put everything together yet in terms of being Superman.
More recently there are have been DC YA novels that featured a teen Clark doing heroics. There was a trilogy of Lois Lane novels where a teen Clark gets to do some heroics at the end, but is mostly Lois' series and Clark is mostly an on online boyfriend for that series. There was the DC Icon novel Dawnbreaker that featured an evil corporation that kidnaps and experiments on immigrants in order to turn them into super soldier slaves and Clark has to stop them to without revealing his powers. All these novels feature a teen Lex Luthor as a sketchy side character, where he is not villain but not heroic either.
What do you think, would you want a return of a costumed Superboy or a Mini-series where a not costumed teen Clark fights crime and saves people in Smallville.