Is topping up CPF via RSTU actually worth it?

Did RSTU for two years then stopped, and here's my lesson. I topped up chasing the tax relief without thinking about liquidity, then a family emergency hit and I couldn't touch that money. Felt terrible watching it locked while I scrambled. So my advice, only top up after your emergency fund and insurance are settled, and only money you truly won't need before retirement. For the right person with spare cash and a filled emergency fund, the guaranteed 4% plus tax relief is a solid deal, genuinely hard to beat risk-free. Just never let the tax relief tail wag the dog and lock up money you might need. Liquidity first, optimisation second.

Been doing RSTU top-ups for 5 years. My honest view, it's worth it for a specific type of person, someone who wants guaranteed risk-free returns and has stable income to spare. The SA gives around 4% guaranteed, which beats most fixed deposits and bonds with zero risk, plus you get up to 8k tax relief for topping your own account. But, and this is the big but, the money is locked till you hit the retirement withdrawal rules, effectively very long term. If you're young and can stomach market risk, a globally diversified portfolio has historically beaten 4% over decades. I do both, top up for the tax relief and the safe portion, invest the rest for growth. Don't put all eggs one basket.

Contrarian take, for young people I think RSTU is often oversold. Locking money away for 30-plus years to earn 4% when you could compound in equities at a higher long-run rate is a real opportunity cost. The tax relief only benefits you meaningfully if you're paying decent tax already, if you're in a low bracket the relief is small. I'd rather keep liquidity and invest myself in my 20s and 30s, then consider topping up nearer 40s-50s when the lock-in period is shorter and the tax relief matters more. That said, if you have zero investing discipline, the forced lock-in of CPF is a feature not a bug. Know thyself.