As others have said, the SLR is the only game in town for macro and for telephoto over 135mm. But if you don't care about macro and long telephoto, then why not take the RF? I have been to numerous national parks and natural wonders over the years, and I usually took only a Leica and the classic trio of 35, 50 and 90mm lenses. In recent years I've sometimes added a 25 or 21.
A tip: A 90mm RF lens at its closest focusing distance is roughtly equivalent to a 50mm "normal" SLR lens at its closest distance. Not macro, but often enough for that plant you just *have* to shoot.
A compromise might be to take the RF and the two or three lenses you use the most. Also take the SLR body, but with one very short lens, one long lens or the 80-200 zoom, and maybe a macro. See what you actually use. Then only take those things on the next trip.
Click here for a 3-page album of pictures from Central Oregon, Crater Lake National Park, and points to and from there and Seattle. All with an RF and 35-50-90, plus a couple of 21mm shots. Makes for a light bag, as
this native of Glacier National Park discovered.
Attachment below is also from Glacier, 35mm lens.
Hope this helps,
--Peter