There are elections but a combination of gerrymandering and honestly just good governance by the ruling party has kept them in power. People genuinely like the PAP. To the extent people vote for opposition candidates, most people would readily admit they do so only to send a message to the PAP. Most Singaporeans do not sincerely want to be ruled by anyone else yet.

Unionisation in Singapore is very different than the rest of the world. There is one very large union (the National Trades Union Congress, NTUC) but it mostly works with the government and the PAP and has a bit of a revolving door with some PAP MPs serving as leadership in NTUC. Wildcat strikes are illegal, and striking is generally not allowed. I think the last sanctioned strike by NTUC was in the 80s. The union does still generally represent workers in disputes between employers and the government and does other work on behalf of workers (trainings, some welfare, it runs the largest grocery chain that at least theoretically is supposed to be a social enterprise and a cooperative), so most members I think accept the arrangement, for what it's worth.

The ruling party has perfected the art of using legal and social pressures to fracture any competing parties if they get too big.

They have a jealously guarded media monopoly and viciously crack down on opposition bloggers by suing them into bankruptcy using absurdly strict libel laws.

As a last resort they steal any policies which make the opposition popular. This is actually an underrated means by which Singaporeans exert democratic pressure on the government but it makes it pretty demoralizing to be in opposition.

There is a national union but it is controlled by the government. Striking is illegal iirc, but membership will get you discounts on your shopping.

Singaporeans are pretty apolitical on the whole, which is how the PAP seems to like it. Theyre not like Americans - not split into two herds who are trained to hate one another.