That's... a stretch. China has "reeducation" camps for dissidents and a Great Firewall; Singapore has opposition MPs and overzealous use of libel laws against critics. The two are not particularly alike.
I have heard and seen some stupid takes on Singapore, but this takes the cake.
In the 2020 general elections, the incumbent PAP had its worst showing ever, with ~60% of the votes. There are 5+ other opposition parties that Singaporeans can and do vote for in free and fair elections.
In the PRC, there are no meaningful elections whatsoever.