I'm rather surprised at the nerve of talking about "reviving" RTSs with... remakes and reboots of what are excellent but possibly rather tired IPs. All of the titles listed are most definitely iconic, but surely rehashed classics are primarily made to appease long-time players rather than draw new faces into the fanbase? And, more importantly for an article claiming to be looking at the health of the genre as a whole: where are more recent titles that also enjoyed success or have endured well without such a storied history?
Dawn of War was sitting on its second acclaimed expac, Dark Crusade, when the last "real" C&C title (TibWars) hit market, and revitalised the Warhammer 40,000 tabletop scene with its sheer popularity - and the poor reception of the reboot compared to its earlier expansions is a big pointer to how developing a line further is better than stripping down its core while layering on production polish.
Sins of a Solar Empire came out at a similar time but broadened the scale even further, saw a series of expansion packs further developing relatively neglected aspects, and is still the heart of a rich modding community with total conversions for a number of other sci-fi franchises.
Halo Wars and its sequel were the only console RTSs to see significant success to date (honourable mention to EndWar), broadening appeal beyond the core PC audience - and said sequel was big enough for fans to highlight its art style in opposition to Halo 4 and 5, an style that 343 Industries appear to have embraced with its newest title.
Ashes of the Singularity freshened the whole formula by shifting balance much more in favour of macromanagement rather than raw APM, which has always been seen as a big barrier to entry for the genre - and yet I see it featured more for its Nitrous Engine benchmark than as a game in itself.
Homeworld is a titan from the turn of the century that went from strength to strength - and while the remaster was rightfully lauded, Deserts of Kharak stands tall in its own right despite being made over a decade after Homeworld 2.
These are just the examples that come to mind quickly - I could talk about more titles like SupCom, CoH (and their respective sequels) and how they still hold up well; or about how Total War, while not strictly an RTS, has still been able to iterate on its core formula across 14 mainline games spanning 20 years, dip its toes into the realms of fantasy, and still do well with its recent releases. Yes, the RTS genre has warned and been eclipsed by MOBAs; but to act as if there have been no good titles since the classics of yore and that we somehow need shiny pretty remakes of them to save it smells distinctly of overly rose-tinted nostalgia at best, or smug elitism at worst.
Or have we forgotten just how well Warcraft III: Reforged went down?