Use project added to Case 1108597 to reproduce.
Opening the project in Unity 2019.1.0b1, suddenly contains various packages I don’t need, such as the “Rider Editor” and “Tilemap Editor” packages. Pretty much every package in there to be honest 
Why is Unity adding them automatically, silently causing the project to grow and get slower, rather than staying lean and let the user choose what to import?
Yeah, I created a thread asking that only Package Manager UI be installed when we create a project but nobody ever answered it.
There’re definitely a lot of excess packages in a new Unity project.
My dream setup would be a Custom Template in Unity Hub, with all the packages that I usually use - and maybe also some assets from the store.
Perhaps they were included by default, so all the hundreds of assets that are expecting those to be part of unity don’t break in 2019.2? Like Unity.UI is now a package, and could break possibly thousands of assets.
A lot of systems already built into Unity are now packages, so they have now included so projects don’t break moving forward.
First they make Unity lean and then you can add/remove these packages if you need/don’t need them. These are coming from Unity, nothing new.
Maybe I am the one who is misunderstanding but I dont think Peter is talking about the fact that Unity is creating more and more packages - I think he is referring to how packages are added automatically to his existing projects when he updates Unity, without being asked. Because we’ve definitely noticed this too. Unity silently fiddles with your packages every now and then when you update Unity.
Yes. The point is that as they move code out the base unity, and into packages, they have to automatically add those packages when you update or they will cause everyone’s projects to break, and cause assets that people import (that rely upon that code) to break. For example, Unity.UI has become a package. That must be used by thousands of projects and assets.
It’s not making anyones project bigger as they update. They’ve just moved the code from point A to point B.
Imagine you’re using Rider. Unity moved the support code from core to package but failed to add it to your packages. Your Rider-connection fails miserably. What do you do? You come here to the forum and you’re asking for help, your Rider suddenly does not work.
Unity chose the better way: they add these packages automatically and you can remove them if you don’t want them.
BTW, even with this solution, there are some cases when the Unity UI package didn’t get imported properly. 
Imagine if they don’t even try… It would be a swarm of users writing “UI stopped working, Unity ruined my game”.
I install it manually. What’s the problem with that?
Unity keeps adding the analytics and ads and in app purchases packages with updates. These have been packages for a while so I don’t know what you’re all talking about. I must have removed them a gazillion times by now.
These, and others… I spend my time removing them too. Sigh.
I’ve nagged a lot of this bloat ever since Package Manager has existed, it’s just become worse each release. You can edit the default package template but it’s useless as next version will have it’s own template again.
I wish I could at least blacklist packages I never want to install automatically for any Unity project (that would apply to all Unity versions).
This, enabling/disabling packages globally would really help this. Im getting so tired of removing the same 10 or more packages every time I make a project
Here’s a workaround which requires you to remove unwanted packages only once:
This doesn’t really work when Unity adds yet another new package though as those would still be added again, and they do it all the time. This has annoyed me so much that I’ve thought of writing a small tool that forces my own blacklisted packages out of each engine versions default template.
What I do myself atm is that I just create new project but manually edit the packages/manifest.json in text editor to get rid of the extras, it’s usually the fastest way to remove the clutter, still annoying tho.
Same here, I use Ironsource mediation that already have UnityAds in itself.
I can remove Unity Ads in packages/manifest.json from local but cannot do it in cloud. Now I have to exclude Unity Ads from mediation, that’s really annoying.