I don't think Lenovo are trying to pitch this to people who already have a tablet with a 120hz display. This does seem a bit overpriced though, at least when compared to the cheapest version of the Tab S7.
I think the reason why someone may buy this is because it isn't Apple, Samsung or Huawei. Lenovo still provide close to stock android and that is an attractive option for those who dislike Samsung's approach. This seems kind of like a large Pixel 4a, performance wise – good enough for many, if not flagship level. Unlike with mid/high tier smartphones though there really isn't a lot of choice when it comes to mid/high tier tablets.
I wonder why it has taken Lenovo so long to release this, after announcing it back in August. Even allowing for Covid it seems like an uncoordinated and uncommunicative approach – if they actually want people to buy it.