But have you not understood there is a difference between being deficient and being insufficient and being optimal?

It like being in debt, actually covering your day to day expenses, or having money to spare in the bank.

For your vitamin d hormone system to work properly you need spare d3 in the bank.

Your body only stores D3 above 40ng 100nmol/l.
You can only have reasonable amounts of assets in your vitamin d savings account when your 25(OH)D is over 125nmol/l 50ng.

You may be happy not being deficient, lots of people are happy when they clear their credit card debts, but they will be even happier when they have a solid measurable amount of savings in their savings account so that any emergency has the funds available to deal with it instantly and effectively.

Until your bodies D3 reserves have been established you remain as vulnerable as the person with no instant access savings available.