Since TeamViewer is a German company I looked up the rules for a non-compete clause in Germany (https://de.wikipedia.org/wiki/Wettbewerbsverbot#Nach_Beendig...):

1. It can only be valid for up to two years after your employment ends.

2. Your former employer has to continue to pay you at least half of your last salary during the non-compete time.

Point 2 is interesting. From the employer's point of view, it must effectively act as a high tax on non-compete clauses, still stopping short of an outright ban.