Of course you should maintain reasonable, adequate liquidity. But there's a very, very high cost if you want to maintain unreasonable, excessive liquidity. If your objective is maximum liquidity, with no other considerations, then among other things you should
never buy a home, especially not a HDB leasehold. Direct real estate holding is highly illiquid. You cannot even borrow against a HDB leasehold. There are only two ways to tap HDB leasehold equity: (1) sell the unit, or (2) if you qualify, the
HDB Lease Buyback Scheme.
Please bear in mind that once your Retirement Account is at least decently funded your OA and SA become a "piggybank" from age 55 onward. (And on your 54th birthday "excess" OA+SA is basically like a 12 month fixed deposit.) Any more dollars that go into OA and SA you can withdraw at any time (in the reverse order). OA at 2.5% interest is currently clobbering every fixed deposit in Singapore, and SA at 4.0% interest is pretty incredible. These assets are also globally well protected from creditors and court judgments. These particular savings
are fully liquid from age 55+...AND you're getting an incredible interest rate. What's not to like?
Also please bear in mind that the wealthier your future self is, the more liquidity you can safely tap today. That is to say the harder your savings work (even in a liquidity limited fashion), the more total wealth you have, and more total wealth is obviously quite helpful if you want to spend more. I'll use my household as an example. Here are the current, somewhat or very illiquid assets "in the pipeline," with the minimum penalty free availability ages noted:
1. Age 55: "excess" CPF SA+OA savings
2. Age 59 1/2: some retirement accounts
3. Age 62: Supplementary Retirement Scheme
4. Age 62: sovereign life annuity #1(*)
5. Age 65: sovereign life annuity #2(*)
6. ~Age 67: another long-term account
7. ~Age 71: sovereign life annuity #3(*)
All of these deals are great deals, but they do have liquidity and/or availability restrictions as part of the deal. So if that's my future (it is), am I free to spend more today? Yes, absolutely! I have greater
effective liquidity today. Greater total wealth, even if it's arrayed across the future like that, means greater achievable, realizable enjoyment across every age. I recommend it if you're able.
(*) I plan to defer these income streams as long as allowed. Plans can change, of course, but that's the plan.