to not have an advantage that other people have:
The new tax means that the vast majority of working people will lose out.
(Cambridge Advanced Learner's Dictionary & Thesaurus からの lose out の定義 © Cambridge University Press)
to not have an advantage that others have:
lose out on sth I have lost out on tax-free income from £1,500-worth of shares, which I need now I am retired.
to not get something that you expected or wanted:
Pensioners will lose out not only from tax on pension funds but from the windfall tax.
lose out to sb/sth London may be losing out already in the fight for dominance among European exchanges.
(Cambridge ビジネス英語辞典 からの lose out の定義 © Cambridge University Press)
- Cambridge Dictionary