I started acquiring Spanish in June this year. I've listened to 1,200 hours of comprehensible input. I've been listening to 7+ hours everyday. My listening comprehension level is very advanced now. I watch a lot of native youtube content. Some movies and series are still a bit tricky in parts but I'm progressing every time.
I've done the silent period where I haven't been speaking. The reason for this is to acquire a tremendous amount of input and also acquire a good accent in Spanish. Listening comprehension is only one part, there is also the acquisition of the language where you absorb it unconsciously. If one tries speaking early they'll probably have that typical English accent while speaking in Spanish and they'll struggle to form sentences.
I started practicing speaking with conversations around 3 weeks ago. I have around 40 speaking hours. It was difficult at first but the progression happens quite fast. When you've listened to a lot of hours and start speaking, it won't be automatic and fluent though. It's the same for infants when they start speaking after a long silent period, they'll understand everything that is said to them but they'll make mistakes when they do start speaking. If you have children, you'll remember them attempting to talk. It's the same for us adults. It's actually easier for adults because they can already speak.
Every hour I do I get better. The level I'm speaking at now is around B1 - B2. Even after a long silent period, there are a lot of mistakes but that is totally normal. With more speaking practice and more input those mistakes will eventually be corrected.
We all acquired our native languages in the same way.
Language acquisition through input works without a doubt. If you're really interested in acquiring [ not learning ] a language give it a try.