Ladybird was mostly developed by one person (Andreas Kilng) with no financing whatsoever ,Servo was mostly developed by a team who was being paid with Mozilla money.
That was true at the start, but it's most definitely funded development now and that's what will probably get them over the finish line.
If the development work went into debating, specifying and expressing required behavior as a written spec more exactly (beyond w3c specs and towards the more pragmatic reality of what current browsers actually do) then very long term we can probably have engines that are AI built [or just more easily developed by humans] from a combination of the written specs and the set of tests they need to pass.
Using AI for adversarial development (e.g. one group tries to break and hack it, the other group defends and refines) could get interesting and wasn't really an option before. Anything that's now available to reduce the human resource cost of development could make a big difference.
> So Andreas working on webkit means he has no browser engine experience?
Who said "no experience"? (except you, of course)
I've said, an I repeat myself so maybe this time it'll work, Andreas had no money whatsoever, while Servo was developed inside Mozilla that poured millions of dollars on it and created a dedicated team to build it.
It makes all the difference in the World, the actual experience on building a web browser is irrelevant, given the initial disparity of time, money and resources available.
It makes all the difference between a random guy building a working twitter clone and Meta building a working twitter clone.
The first one is an amazing accomplishment, the second one is a mehhh at best.