Actually, it’s WN that’s building up in CLE. In 2017, WN surpassed UA as the dominant carrier. They have increased flights by 13 percent since then, making CLE a pretty decent operation for them. If Frontier did not come to CLE, it would probably be a focus city for them.
Right now, UA carries about 1.6 million pax per year, and WN carries 1.7 million per year.
That can’t include United express partners, and the comment on WN and focus city I don’t buy, not even close. WN votes again and again— before and during F9 presence— that CLE is a pretty trivial station, starting with no daily service to DAL and HOU, unlike CMH and PIT and IND. One could argue that a piece of WNs growth in CLE was shutting down CAK.
Furthermore why would WN even need a focus city in between MDW and BWI.
ncflyer is right. Looking at Oct 2018 info:
WN is 17.3% of the market
UA Mainline is 18.4% and
UA Express is 8.4%
So in terms of public branding and ticket sales, UA, at over 25% of pax, is still the largest carrier at CLE.