I would also give (outdoor) plants as gifts. From little bulbs to trees, there’s something for every budget (and every occasion), and usually people don’t have the money for that after building a house.
I wouldn’t exactly be happy with just any plant either – I have favorites and ones I wouldn’t want to see again in my own garden. That’s why I’d rather give a gift card. I also find an insect hotel quite questionable – would someone really want that?
I think the idea with the plants is actually a nice one - but I would ask beforehand what they would like or just give a voucher. Although the idea is nice, that you then get exactly "that" bush from you