Not too many, the GF concept has hardly struggled has it.

Trouble is the RFL will feel the top eight is justified due to the performance of Catalans in the play offs. It wasn't 7 & 8 Cas and Cats who were disappointing but 3 & 4 HKR & Hudds.
Cas went well at Wigan and Catalans were superb even at Leeds.
HKR & Hudds were awful and both club's end of season games were poor.

I do think there should be more made of coming top of the League.
The LL Trophy now doesn't do it justice.
Bill Shankley's said about it , First is first and second is nowhere!

The play offs are down to money and SKY's influence. The play offs and the GF put a lot of money into the RFL and clubs. Money neither can do without.
The GF is here to stay, the play offs will be over four weeks. After that the format can be managed as the game wants.

But this just de-values the comp because you are allowing mediocre teams who have lost as many games as they've won into it. A lot of clubs' ambition dosen't stretch further than aiming for 8th place. The top teams are consistently making the final because they are simply the best, not because of a system that is "unfair" to the clubs finishing lower in the table.

Sadly I think you have it spot on, to give the end of the league stage a bit more oomph the need to put some money on the line otherwise clubs will continue saving players for the end of season games.

If a significant monetary prize was awarded it would make it all the more important to the men at the top - I vaguely remember the all conquering Wigan only started taking the previous "Premiership" tournament seriously when the prize money became significant around 1992 when they previously treated it almost as a reserves match