Awhile ago I had a look at Hindawi journals and found out that:
-71 of their journals were indexed in SCIE (in 2019) so with impact factor
-107 journals were indexed in ESCI (in 2019)
-179 journals are indexed in Scopus (2020)
-229 of their journals are included in DOAJ (often used as white list for open access journals)
-Member of OASPA and COPE
So I think it is not that dramatic. Total of journals in ESCI and SCIE is approx. the same as the total number of Scopus indexed journals.
I think the (main) difference is that Scopus indexing starts sooner (and Scopus use around two years to finalize their evaluation) while indexing in SCIE only starts after some years indexing in ESCI and once found eligible inclusion in the SCIE starts (and an impact factor is assigned).