The 81k is slightly misleading anyway, their actual total value for the work they do easily pushes 6 figures due to additional perks and expenses. Someone elsewhere compared it to a GP salary and said MPs should get even more, ignoring many GPs work under as much stress if not more than MPs, need to go to Uni, train from junior, prove their competence and can have serious consequences for gross incompetence. They have few perks or assistants.
MPs just have to win a popularity contest at worst. At best they simply have to turn up with the correct badge. They have a whole civil service their to enact their wills (or obstruct if Yes Minister is anything to go by). Their biggest worry is about brown nosing to the PM and ministers. They can be extraordinarily incompetent and still maintain positions of great power. If the job was as difficult as they claim to justify the extra money then they shouldn't have time to do this stuff on the side. I think the very fact they are able to fit in plenty of stuff on the side on top of being an MP clearly indicates it is not as difficult or time consuming as they claim it is. Any claim they need more money to simply live is laughable tbh. Yeah MP isn't as high paying as some other things but it shouldn't be either. There is also no evidence that paying them even more does anything to lessen corruption. So of the most corrupt people are also insanely wealthy even without their corruption.