Are retirement/endowment plans from insurance companies a good way to grow retirement income? Or are there better alternatives?

Definitely! When planning for retirement; there are needs (living expenses, utilities, medical costs) and wants (holiday, hobbies, country clubs).

Retirement plans provide a source of GUARANTEED income to you that could ensure that your needs are taken care of. If it was just purely on other types of investment vehicles, you may suddenly lose that source of payout during a bad year. Think of the current climate, if you had invested in eg. hyflux bond / banks, you'd probably be down by alot and wouldn't want to liquidate your investments at a loss. They're not the ONLY plan that can be used to plan for your retirement, but are definitely a place to start.

Think of it as having a pay cheque (needs) and a play cheque (wants).

Low risk products can help to take care of your pay cheque.

Eg. CPF Life, Annuities (retirement plans), Supplmentary retirement scheme (SRS)

Higher risk products can help take care of your play cheque

(stocks bonds property, REITS, etc.)

A comortable retirmenet would usually encompass a mixture of both. At your retiremnt age, it is unlikely that you have another 10-20 years down the road to work and make back the income if your Investments had gone south.

There is a variant of endowment plans called Traded Endowment Policies/Plans (TEPs) which is pre-owned endowment policies that was bought-over and then re-sold by 3rd party brokers. The projected IRR is between 3.8% and 4.6%, and is usually higher projected IRR and shorter term to maturity as compared to newly incepted ones for the same policy structure.

Disclaimer: I co-founded a business trading insurance policies.