the thing is algorithms just amplify what you were already watching. they show you more content similar to what interested you, but they don't force you to scroll for two hours - that's you clicking. the real problem is more that the system is built to be addictive so your willpower gets weaker against how easy it is to use. but it's still your choice to keep going or close the app.
what changes is the *clarity* of your decisions, not your freedom to make them. before you'd go to a store and see what was on the shelves; now they offer you an entire shelf generated just for you. it's more efficient, yeah, but also more persuasive. if you feel like you're not deciding anymore it might be because you didn't really think about what you wanted before they showed it to you.
the existential question is legit, but free will was never black and white anyway. you've got influences everywhere - family, friends, regular ads, everything. this is just more targeted and constant. if it really worries you, put your phone away for a day and see what you actually miss versus what the algorithm thought you wanted. often you realize you had your own desires, they were just buried.