Don't quite get OP's point.
FCT is a lounge like many others , maybe just a bit better.
Not an expert in mileage tickets , but seems to me like taxes are not LH's doing.
And upset because there is no F welcome / arrivals lounge in FRA / MUC , which OP would not use anyway as he wants to get out as soon as possible.

Is HON worth it ? If you fly enough you will be a HON , or similar on other airline if they have that level tier. If you chase the most economical ticket every time, chances are you will not be anybody anywhere 😁

My main disappointment with LH is their cut back on F to many destinations . And with a mediocre business class at best.