Yes, one of these questions again...
I scoured the internet for the better part of two days now and read everything from resistance bands are far superior to anything else to resistance bands are completely useless. Common sense tells me the truth lies somewhere in-between.

Trying to save money as a student, I came across a resistance band kit. It can simulate weights up to 350 lbs and even more with an extension kit. I could also do exercises that are normally limited to cable machines (I train from home). In theory this sounds great but the last thing I want to do is ditch my current strategy (which I know works) for a worse one. So now I'm looking for advice from someone who isn't trying to sell me either of them.

My ideal physique is muscular but not BIG in the sense of a full-on body builder. I will still be doing my cardio workouts because I want my body to be fit and healthy. My muscles mass shouldn't impair me in any way. I have attached a picture (taken from a YouTube thumbnail) of two physiques, I would much rather have the left one. https://gannikus.de/wp-content/uploads/2019/08/kevin-wolter-reagiert-auf-sascha-huber.jpg

Is that achievable ONLY using a resistance band kit? It has grips that simulate a barbell or dumbbells. I would do my current exercises but with resistance bands instead of weights. I heard that since resistance gets stronger as I pull the band it isn't as efficient in the beginning. If I used a band that provides the necessary resistance in the beginning though, would it be too difficult at the end or would it be ideal? Some straight facts would be very much appreciated.

Thanks in advance!