There is a trade off in photography where you either go for image stabilization or a faster lens. Google chose the faster lens which I very much prefer as a photographer.
No, there isn't any tradeoff. Not sure who is feeding you this junk. I have been using OIS lenses since 1997 (Canon ES-970, first consumer camcorder with OIS has f/1.8 lens, faster than Nexus 5x and Nexus 6P). You can have both. When subject is moving, you need fast lens. When subject is steady and you don't have tripod, you need image stabilization. OIS can give you 3-5 stops advantage while new Nexus lenses are only 1/2 stop faster than 2 year old Nexus 5.