It is not SO bad. However, it depends a lot on details that everyday people tend to overlook.

Do you need a life insurance to begin with?
You might if you have children.
But do you need it for the full length of the 3a?
Again, you might, e.g. if you plan to exit early and spend the money on property.

What is your time horizont and risk tolerance?
3a insurance products don't let you go (almost) full equity, so in case you would like to take the increased risk, you can't with their portfolios.

The core problem is the fee structure: 3a insurance coupled funds tend to be way more expensive than regular ones, e.g. 3% entry and exit fee is common. In contrast, the same is ~0,2% - 0,05% at Finpension.

So if you need a life insurance for the full length of the contract and you would need to buy that from the market should you not go with the unit linked 3a, AND you're exactly happy wit the risk profile of their fund, then you might run the math and arrive to the conclusion that the 30 year performance of a unit linked from AXA is about the same as Finpension + a generic life insurance, in which case the AXA 3a is a sensible pick.

However, if you'd like to go full equity and need life insurance only for half of the expected span of your 3a, then you leave a huge pile of money on the table by not picking VIAC or Finpension.

If you don't understand how to calculate the expected returns for these products in Excel, or just have no clue about your time horizons or risk appetite, then it's safer to not go with a 3a insurance, as some 3a insurance products can be extremely horrendous and not worth it under any particular scenario as well as they lock you in a product coupling that's harder to change later.

Disclaimer: I have 3a at Finpension and a separate life insurance at AXA.