When you buy a Video Card, you match it with whatever screen resolution and framerate you want for your gameplay. 60fps is typically considered the target because there will be no lagging, input lag, reduced or no stuttering.
The GT 1030 can play the newest games at 1280x720 or 720p. It can play most games at 1600x900, and a few of the newest games will run at 1920x1080 low settings.
The GTX 1050 can play the newest games at 1920x1080 low to medium settings.
GTX 1060 is rather vague because there are 2 different version of the card. Nvidia had no business ever releasing the 3gb model since it has 11% of the shaders/processors cut which makes it 11% slower than the 6gb version. In all reality, the 6gb version should have been called the GTX 1060ti. The 3gb version is what you probably picked and it's good for 1920x1080 medium to ultra settings, and it can play a few of the newest games at 2560x1440 medium to low settings. The card will be handicapped in some games by it's limited amount of VRAM.
For 200 sterling, the GTX 1660 or an RX 580 probably would have been a smarter pick, in which case it costs 200 to 220 sterling depending on the model.
The other problem here is you really need a 450w power supply for anything above at of above the GTX 1060 or GTX 1660 as these cards consume about 120w. The GTX 1050, GTX 1050ti, or the forthcoming GTX 1650 will work well with a 300w power supply because these cards consume about 70w.
If you have a 300w or 350w power supply and you're using a PCI-E 6-pin adapter to hook up your GTX 1060, I would STRONGLY advise for you to upgrade the power supply to a competent 80-plus Bronze 450w model.