And sometimes the unscrupulous third party decides to build a browser and take over the market via forcing hardware vendors to bundle it with their OS. Like Google.

so, it should not be updated automatically. so, you should not trust something that install updates (literally - install another software) without your agreement

Back in the mid 90s when the web started to be all the rage, I remember reading a comment I thought hilarious and kind of right. Paraphrasing a lot it went like this:

"Somehow, when people get into the internet, their IQ decreases like 50 points. Like, if a guy knocked on your house door and offered you to give you a million dollars if you just gave him a thousand now, you would tell him to F. off. But somehow on the internet people thing it's right"

Same with these apps, someone comes and tells you to let him install this great water appliance for your backyard. You let him come in. But somehow in the internet, you also give him the key so that he can come in again anytime he wants... he may sell the key, lose the key, do something malicious later,etc. But due to ignorance, people dont grasp what they are doing in the digital world. People lack the necessary mental models.