Hiya and welcome ^^
I’d say plenty of people learned kanji through WK, but of course not Japanese as a whole.
If you’re pretty new to learning Japanese, I think it’s wise to avoid overwhelming yourself, as you mentioned. Learning a language is a multi-year endeavour, but many people feel that initial enthusiasm, bury themselves in material and then burn out switfly.
The official Tofugu advice is getting a WK routine established until about level 10. Then start grammar, and start reading as much as you can in the level 20s and beyond. I’d say it’s pretty solid advice, because WK alone can be quite a lot to keep up with (depending on lesson speed and how often you can do reviews). But it’s important to pick up grammar the moment that you can.
For me personally, it was 4-6 months of mostly WK, then grammar via the CureDolly youtube channel and through BunPro. Yes, the visuals and audio for CureDolly are awful, but I lovelovelove the method of Organic Japanese - learning Japanese as Japanese, and not by way of English/Western grammar. I’m also not a native English speaker, so equating JP grammar to ENG grammar is useless to me.
Now I try to read as much as possible, because WK teaches you kanji. There is a huge amount of helpful vocab that WK teaches you, but there are also vocab words that don’t get used that commonly, or that don’t tend to ever be written in kanji when they are actually used in Japanese text. Reading and listening is the only thing that will teach you common from uncommon word usage.
That’ll wrap up my rambling answer, I’d say. Very best of luck, and I hope you’ll love this Japanese journey as you work towards that trip of yours! 頑張って！