Why are two tax regimes shown, with no recommendation?

In France you can choose between two ways of being taxed on your gains: a single flat rate, or inclusion in your income tax (the option is ticked on your tax return). Which one works out better depends on your personal situation: your other income, your household, how long you have held the securities.

Earnnest shows both side by side, with the amounts calculated, but does not tell you which to pick. That is not an oversight: recommending one would amount to giving you personalised tax advice, which Earnnest is not authorised to do.

You will notice that for the progressive-scale option the income-tax amount is not calculated. That is normal: it depends on your personal tax rate, which Earnnest does not know. Showing a made-up figure would be worse than showing none.

To decide between the two, your tax office or an accountant is the right person to ask.