My Huawei Mate has displaced my Canon GX that I no longer carry in my pocket because my mobile works better for me That size is the paradigm shift. Optics should I buy This is not so easy to answer because there are many types of tools to solve different photographic situations. Fixed focal length lenses. I like prime lenses because they offer the best optical quality at an affordable price. There are two lenses that seem great to me because they are ideal for street photography because they are compact the Canon pancake is incredibly discreet their optical quality is really good the focal length is very useful and the price is frankly affordable.
Without a doubt I would start by e-commerce photo editing buying a Canon EFS mm STM equivalent to about mm in cameras with APSC sensor € Well nice cheap and small. In cameras with APSC sensors it is equivalent to a medium telephoto of about mm. It's great for taking portraits. Good pretty and cheap. But not very versatile. Canon Variable focal length the super kit Basic cameras usually include an mm kit lens equivalent to mm on APSC cameras. There's a good logic behind it the range of focal lengths on these lenses spans from wide angle to normal to short telephoto so there's a lot of versatility.
But the classic kit is cheap and with many compromises in optical quality in exchange for being as cheap as possible. That's why I prefer what I call the super kit which has practically the same focal length but with first class optical quality constant f. aperture and optical stabilization. Yes it is an expensive heavy cumbersome but ultraversatile lens that could be mounted on your camera of the time. It is the one I usually use on APSC cameras unless you have a project that requires very specific optics. Interestingly the Canon version is stabilized a plus ultimately and the Nikon version is not. Buy it only if you really need it but make sure it's a good one There are no half measures.