I periodically think of getting one, but it would only work for a section of the house, albeit the section that could use the most regular vacuuming. But that same section is also where there tends to be the most clutter/cords laying about, etc.
In the end, my compromise was to get a good cordless vac which I can run for a few minutes if the crumbs and other debris get too objectionable.
Regular vacuuming makes carpet last longer because when grit gets between the carpet fibres, it acts as an abrasive and literally wears your carpet away with every footstep.
The trafficked areas the Roomba would work for mostly don't have carpeting. And where there are carpets, they're all decades old so I'm not too worried about taking new steps to prolong their life.
In the end, my compromise was to get a good cordless vac which I can run for a few minutes if the crumbs and other debris get too objectionable.