Dropping marketshare for others may not mean falling business. It's possible that the market size is growing fast enough for the commercial ones to actually be seeing a growth in business.
https://w3techs.com/technologies/history_overview/ssl_certif...
Every CA is growing except StartCom who were distrusted by most players last year (and Microsoft, belatedly, remembered this year) and have recently declared they're throwing in the towel, won't try to get back their trust.
The big categories which shrank are "None" and "Invalid Domain", ie people who didn't have SSL, or were on shared hosting and never switched it on for their site or whatever.
How about cPanel and others who bundle Comodo certificates?
No, I think Comodo are doing very nicely off this. They've correctly judged that they're never going to be the Maserati in this industry they need to be Ford or Toyota and too bad if some people sneer.