> mistakes in your form that you do not even realize.

form is entirely overrated in lifting. There's little evidence that a particular way of moving in the gym is more or less injurious, even if it looks funny. Efficiency is another matter, but don't nocebo anyone into not touching barbells in fear of "bad form".

And while coaching is surely useful, it is entirely unnecessary for a beginner who just wants to get started. You can make plenty progress for years without a coach, but it might be faster with one.

> And if you are a beginner, any attempt to do these exercises will invariably contain so many mistakes that they are not worth doing any more.

this is also clearly untrue and way too generic. Even inefficient lifting is healthy. Youtube is all you need to get started. There's plenty dumb info there, but plenty good also