What did he mean by this

There is one counter argument I can think of which seems improbable to actually occur:

• the foid is over 18, the moid is under 30

• the local laws mean the foid is of age (AoC and legal drinking age etc)

• the foid has a good family she isn't trying to escape

• the foid wants to optimize her 20s for education, career, travel and life experience

• the foid wants to settle down with kids by 30

• the moid is aware of the foid's intention and wants / is able to satisfy them

In that case, and that case only, it can work without being exploitative. The foid is getting the best possible use of her 20s, and is not being stunted in her social development or career prospects.

The moid gets to spend his 30s in the best possible way with a foid who will rapidly surpass her peers. He will have a family life by his 40s, she by her 30s.

This is rare because most foids at that age are fickle and capricious, and most moids of any age are lazy and duplicitous and will try to trap the foid before she realizes he isn't what he said he was.