It would be a weird kind of bad situation, if literally thousands of juniors with little to no experience/understanding of programming simultaneously start learn-as-you-go contributing C++ code for Ladybird.

In the perhaps more plausible situation that two or three people with a reasonable foundation in CS and/or a bit of professional programming experience decide to learn C++ in order to help Ladybird, I think it would work out quite fine.

I had to think carefully if I would ever agree with 'plausible situation' at any point of my career. And the answer is no. If they really needed 2-3 ppl they would have adjusted their sponsorships/donations plan and picked up those ppl full time. There are costs of bigger teams and wider contributor networks that are rarely advertised.

But ofc what can I know about browsers, I am just a gamedev. From my PoV (studio tech director) in custom game engines juniors mostly do acts of wanton destruction in the name of curiosity. And then leave for better compensated industries anyway.

In my opinion folks inciting random contributions from webdev crowd unfamiliar with C++ are not helping. And those who are familiar should know better than to do random drive-by features.