Funds deposited on Qonto are stored in a ring-fenced account supervised by the ACPR (French institution responsible for supervising banks), attached to the Banque de France.
Nobody other than you can access your money. Neither Qonto nor anyone else can use or invest your funds.
We have no intention to go bankrupt, but if this had to happen, your funds will not, in any case, be impacted. In this extreme scenario, your remaining account balance will stay untouched and will simply be restituted to you in the bank account of your choice.