LH improved the FTL/C lounges over the last couple of years and started offering more (hot) food. Some new openings certainly helped the cause.
The average AF or KL lounge used to be better, but AF did not invest as much over the last couple of years and some stations were pathetic (DUS, BCN come to mind quickly)
In FRA last week, they offered three different sandwiches (the toast triangle) two small pizza snacks (from Nestle-Wagner) salad (small mixed salad with art. goat cheese) and a variety of steamed veggies, which did not look too appealing. Cake was also offered as well as wine, beer and soft drinks.
The variety is superior to what LH offers at most FTL/C lounges, but cannot compete with the more upscale lounges.
KLM used to have the same approach as LH, Silver Wing/C and Royal Wing/F , but they discontinued F and the Royal Wing lounge later on to come up with the current approach, which is solid in all terms, but often too crowded.
The tuna salad is actually tasty and a definite improvement over the Salsa and Guacamole days from the last decade.