Youtube is too childish to me, on Instagram there's not soo much to see, and otherwise you can't do too much against boredom on the internet.
I mainly use Spotify and Netflix.
I would need a platform that would suit me but also have a certain level. (I do not mean good question)
Spending the whole day outdoors is out of the question.
There are certainly alternatives between "spend the whole day outside" and "bored on the Internet". Even youtube and Instagram are very diverse, maybe you are looking for new topics there, topics, which also stimulate you to activities in the RL. It's not the platform itself that is boring, but the stuff you consume. If consuming is boring, look for ideas for offline activities online and then practice them! Passive consumption is always boring than active action!
PS
How about specialist forums, blogs about subject matter or subject matter, through which you learn something new that you can also partially test offline? Maybe a topic that you have never dealt with?
Where is YouTube too childish? If I look at some pubescent creators, I'd say it's true, but there are so many interesting channels coming from older ones. For example, a few days ago I found an English Youtuber that immediately inspired me. He is an older gentleman who understands a lot about steam engines and their production (this is my hobby) and as someone who has not learned a metalworking job at all I can learn a lot from someone who has learned that.
