It is a poor deal to pay the monthly card fee using miles. For instance, if you pay the personal gold card using cash, it's EUR 11.5 per month. If we assume a M&M mile is worth 1.3 cents, that means you break even at a monthly spend of a little over EUR 1770. (More if you have a lot of small amounts indivisible by 2.)

It is worth noting that the card may offer other things valuable to you (such as protection from mileage expiry, insurances, etc.) and that there are occasional promos which effectively bump up your earn rate a bit. There is also a sign-up bonus which should be factored in (which is occasionally increased during promos).

Still, why is the earning so little compared to US, Australian, or UK cards? It has to do with tight consumer regulation in the EU. For instance, France caps APR. Then, there is an EU-wide cap on interchanges for personal MC/Visa. There is also more "transactor" credit-card use in the EU (in fact, most M&M cards are charge cards and don't allow ANY revolving usage). The issuers of charge cards have no interest income. You should really Google for yourself if you want to learn more about this.

Obviously, if you continue to have access to international cards, those might continue to be more attractive (but by mindful of FX fees and such).