First of all, this is a rather good threadmill, since it is stable and goes up to 17 km/h for a good price. At least they say so.
First negative thing, that you notice - the clock goes wrong. After half an hour you already miss one minute. Then, the speed. 5 km/h feels to slow. 10 km/h feels to slow. Not sure about 15, 16, 17 km/h, those feel quite fast. I have no means to measure it. It time and speed are wrong, how can I trust the distance?
Fat measurement just does not work at all. Heart measurement is wrong. Just for example, when my watch shows values above 150 bpm, treadmill shows may be 90 bpm.
Then, the USB. You can insert some USB stick in it. No idea, which version work there. USB3.0 doesn't work for sure. Another thing, which file system does it support? FAT? FAT32? exfat? It is not documented. The used microcontroller must be the cheapest available, so I just assume that it supports only USB1.0 and FAT16. Not tu mention the supported file format. Nothing of it is documented. Presumably the manufacturer does not now it either. Then you have also the meaningless AUX slot. If you assume the used hardware, probably you don't want to put your headphones in it. But actually we live in 2022 already, people use blutooth headphones. which are wireless, wich are connected to your phone, wich will have much better sound quality, then whatever this hardware can offer. May be the manufacturer should offer a better place to put your phone? He surely didn't. The place for bottles is funny enough not round.
Then the buttons. Lets not talk about music player buttons, you will probably not be able to use them anyways. You have six quick speed buttons. 1 km/h, 3 km/h, 5 km/h. 7 km/h, 9 km/h, 11 km/h. What about the speeds above 11 km/h? Of course there are "increase" and "decrease" buttons, which go in 0.1 km/h steps. But if the manufacturer would throw away all meaningless slots and buttons, he would find more then enough place for 17 quick speed buttons. Why not do it?
Another thing, you cannot put a notebook on the treadmill. It could be, that the manufacturer made it explicitly impossible. So you cannot work and walk on it, and you cannot watch a movie on it either. And you cannot load your phone on it. Worst design revard well earned.