The answer here appears to be simple. Because elections and free speech are aspects of the system that by design introduce certain level of instability, but also a way to channel population frustration thus preventing having to resort to violence.

CCP chose stability of system above all else.

> The answer here appears to be simple.

It was a rhetorical question. The CCP doesn't allow elections and free speech because they don't want to lose power.

> elections and free speech are aspects of the system that by design introduce certain level of instability

That's the standard claim of dictators, including the CCP, but it's just their propaganda. Democratic governments are far more stable. Chinese democracies - Taiwan and Hong Kong - are/were very stable. Japan, South Korea, etc. When was the last time the US, UK, etc. had a stability problem? Compare that to China, North Korea, and the rest.

Also, that claim looks at it only from the dictator's point of view (a natural bias): Will my power last? I might be voted out at any time! I could be criticized into irrelevancy! That would be a catastrophe for the country if my great leadership was removed! Democracies change leaders frequently and with ease; it's rule of law, not of a person (or personality).

Finally, from the ordinary citizen's point of view, democracies are far more stable: Their rights are protected; they won't be arbitrarily arrested, have their assets seized, be sent to reeducation camps, etc.