I’d say a lot of pre-70s Ferrari drivers are forgotten these days. Along with Johansson (before I started watching old BBC coverage on YouTube, I too kept forgetting he drove for Ferrari, or McLaren for that matter.) Phil Hill even won a WDC and isn’t mentioned that often when people are talking about Ferrari.
Wolfgang von Trips is another good candidate for unluckiest driver for Ferrari, crashing fatally in the race you need a 3rd to secure a WDC isn’t very lucky in my books. Jacky Ickx also suffered some terrible luck with Ferrari. Clay Regazzoni, Michele Alboreto, and some others probably expected more from their time at Ferrari, especially Jean Alesi, who I personally consider one of the biggest wasted talents of the 90s.
As for Luca Badoer, I still feel bad for the guy. The man basically drove his butt off to help Schumacher be as successful as he was, but instead of people praising him for his work as a test driver, they bash him for being unsuccessful in a car that Raikkonen only managed one win in, was hard to handle and when Fisichella took over from him, he barely did any better, despite scoring a pole in Spa. He deserved a shot in 1999, he would have scored points for sure.