For most arthropods, I generally consider getting down to genus a meaningful identification – at least when there is not a comprehensive guide to a group (describing all extant species), as there always is with birds. (That is only the case for groups like butterflies and odonates, and only on a regional basis, e.g. for the U.S. or Europe). Family level or above usually doesn't provide useful information about distribution, etc. to anyone.Do pan-listers need to get down to species level for all taxa? I would think given arthropod diversity and difficulty with idea, getting down to even just family would be specific enough.
As to the general question of the thread, I am sure I am over 7500 taxa, and have entered a lot into iNaturalist. But I can't use it to generate a complete list. No way am I going to add all my eBird sightings into iNaturalist. I'm over 4000 worldwide in bird species and I know of no way to add them that would not take an enormous amount of time – it looks like you need to add each observation without media individually noting location and date.