Well, my welds with my Clarke MIG102NG weren't anything to write home about, & thin metal... well - far from easy or pretty - but with decent FC wire in it, do-able. I reckon the wee Clarke can't be anywhere near as bad as some others.It would be very useful, if you included photos of 'old vs. new' in terms of results.
With decent modern hobby MIG kit (Paton / R-Tech / GYS / Jasic / Uptime etc....) it's not too hard for anyone with average practical aptitude to get quite good results quickly, and on thin metal.
Whereas with a '£100' gasless machine, it is or can be, nearly impossible. What happens is that the newcomer decides that welding is not for them and they will never master it, unaware that the lack of technology (and being too cheap) has quite possibly scuppered them.
I'm going to need quite a bit of practice with the new kit to get used to it (& get a feel for and an idea of basic welding level & wire speed combo's) - but my brief tries suggest my welds will be better