This is a difficult answer cuzbecause it depends ion the viuew you have.

We're rarely use "cuz" in written English.

Having the same teacher for years allows hithem to know what are your strengths or your weaknesses, he are. They also gets to know you much more and, with that, the isy are capable of provide toing you a better and more personalized education,. On the otherside hand, changeing teachers every year, also have his its beneficed,ts because you could learn news things with a different method of teaching.

This correction is more for a gender neutral paragraph and parallelism.

What if the teacher you haved before it wasn't that good at teaching different topics?

You cwould only know by having another different teacher and compareing the two of them.

This is subjunctive case so we would use "would" instead of "could" here. I also corrected for parallelism.

Also, it is good thato have a new person analysed your strength, he iss. They are going to look at you by a newfrom a different perspective that no one else have,. A new perspective is always a good thing to have to get better, an changein order to better grow you'rer mind, for the best and not for the worse.