in my exp ya still ppl doing it but not like before, shinez/pubplus type easy setups mostly gone or harder now, u can try networks like AdsMystic or similar agencies but most guys now build own setup instead of relying on 1 company , better way now is run fb traffic to your own site + monetize with adsense/ezoic/mediavine and track with tools like redtrack or voluum, also many moved to native ads like taboola/outbrain + tier2/3 geo for cheaper traffic , so simple answer companies less now, most money is in building your own funnel + tracker + ad network combo not depend on 1 platform anymore.