Did you have your coffee today?
I don't drink coffee.
The problem is that the baseline is that much higher because they 1) have people paid to invest time in building it and 2) have a direct financial incentive to keep improving the product.
If XF 2.0 to 2.1 had delivered a new theme, limited add-on compatibility, a new editor, alerts (because it didn't have it before) and a few other sundry features, do you think the customers would have stayed paying for 11 years in the meantime?
The out of the box experience of XF and IC vs the out of the box experience on any of the free platforms... is night and day difference. You get some cases where there's a hybrid (Discorse, NodeBB, Flarum) where there is a practical and significant hosting component that pays for some development.
Much as I hate to give our dear friend Tracy much of a shoutout, one site he participates in uses SMF and there's been a surprising amount of commentary about how much 'it's not XF'. Some of it you can chalk up to a lack of familiarity but far from all, and more galling to admit, I find myself agreeing.
The likes of phpBB, MyBB and SMF are - sorry to say - second class citizens at this point, irrespective of how much work one individual site might put in to 'prove it's not true'.
And to give you some idea of how much of a stake in this I have made almost 77,000 posts on the official SMF community in my time, released over 100 addons including one used on the official SMF community itself (and two that very nearly ended up becoming official 'Simple Machines' products) as well as tens of thousands of lines of SMF's code. I do not hold this opinion lightly.