If you’ve been living in the UK for five full years on the same visa, you do become eligible for an ILR or an Indefinite Leave to Remain. However, like all matters of UK immigration, applying for a UK ILR and having it approved is not as easy as it sounds.
Considering that the total number of visit visas granted by the UK was around 2.1 million in 2017, it’s safe to assume that visit visas to the country aren’t difficult to attain.