What is the disadvantage if you don't have Google service? (Huawei MatePad)?

I want to buy the Huawei Mate Pad. However, according to the Internet, this has no Google service.

To what extent am I then disadvantaged?

Can I no longer download something normally from the Playstore?

I agree. The playstore is not available at all.

How can I then alternatively download everything? Does Huawei offer a real alternative? Or is the tablet not recommended then? Or. Is it still possible to download everything "normally"?

Playstore and Google Services can't be used, i.e. Also no apps like YouTube, etc.

Huawei offers a search in the App Gallery, which then downloads apps from third-party stores (Amazon for example). Nobody really knows to what extent all apps are available and, above all, safe. Some things, like YouTube, have to be accessed via a browser.

Oh man, it's a shame…

You are also rid of the data octopus Google! Some install extra ROMs without Google to get rid of that.
So, you can't use anything from Google with it, but (almost) all apps are also available as apk files for installation in the following app stores:

https://www.amazon.de/...1000854623

https://www.f-droid.org/ (mostly open source apps)
https://www.apkmirror.com/
https://apkpure.com/de/

just to name the ones I used (previously always virus-free!).

You can find more on the topic https://www.apkmirror.com/

I'm sure you can find a lot about this on the net. It is quite possible that Huawei "self-help forums" exist. But you have to do more research yourself.