That's easy when the PRC is mandating it, but given the hard earned safety record of say... Airbus, people are not in a rush to stake their lives and businesses on Chinese built aircraft. They're not exactly known for the transparency and integrity. In 20 years COMAC is likely to suffer multiple deadly crashes.
- the average 737 MAX 7 aircraft would typically carry between 138 and 153 passengers, range 3,850nm.
- Embraer 195-E2 carries between 120 and 146 passengers, range 2600nm
Scaling into the A320/737 range would need a brand new design with wider fuselage probably. I'm not saying that Embraer could not do that, but sticking with the E2/A220 size range seems to be a winning combo - until recently (A220), they had no real competition from the big two. Maybe with the more recent weakness from Boeing, Embraer might want to consider a 737/A320 class design, but these things take time.
Also, as much as BRICs is a thing, I don't think Brazil would be too fond of selling Embraer to China.