The French Officers and sailors did not surrender their ships to the Germans. They sunk them with their own hands to prevent the German Navy from gaining 3 battleships, 7 cruisers, 15 destroyers and 12 submarines to use against the British and American Navies.
And to show they would do what they said they would do. The English opened fire at a French fleet at Mers El-Kebir in North Africa a couple of years earlier to keep them out of German hands. The French claimed they never would have let the Germans get the ships. Thousands of French sailors died. It was a sore spot between the French and Royal navies for years.
The ships at Toulon were out of the effective reach of the Royal Navy, so they sat there in French hands, until they kept their word and scuttled rather than add to the Nazi fleet.
The Germans started their offensive in May. Took Paris in mid-June. The French sunk their ships in NOVEMBER!
Not like there wasn’t enough time to paddle them to Liverpool for the Brits to use. The German Navy’s Bismarck has long since been sunk. Their navy was nearly completely shot by then. The chances of them being attacked while fleeing to the UK were nil.
They had months to take offensive action or reposition but they sat on their hands.
“3 battleships, 3 heavy cruiser, 4 light cruisers, 15 destroyers and 12 submarines” would have doubled the German Navy - may have been enough to enable them to cross the channel.