Splinterlands: Wild vs Modern Battle

After a long break I just started to play Splinterland. The playing mechanism has changed a lot and a lot of new battle formats have been introduced. I played frontier battle format first time and now I am trying to collect all cards and upgrade them to complete the 15 daily battel tasks. This season survival mode is not working, maybe some awaited changes coming soon. Remaining two formats are wild and Modern, in wild format all sets cards are playable but in modern format only cards associated with Foundations and the two most recent sets Rebellion & Conclave Arcana are playable.

I have a decent amount of upgraded cards in wild format but for Modern I purchased all important cards and still a lot of cards are missing. Splinterland encourages players to participate in Modern format as rewards are higher as contrast to wild format. Although in wild format players pay 2000 Dec token fee and also get cheaper rewards.

If you check the winning rewards of both formats wining rewards of glint are in wild 48 glint and in Modern 115 glint. On winning the battle in Modern I got 132 Glint and 0.21 Sps token and in wild format I got 48 glint and 0.013 sps token.

After analyzing all this I think that participating in wild format is not of any worth so I decided to not participate in it in next season and save 2000 Dec. I also thought that my older cards are of no use case, so I am trying to sold all old cards and to buy newer modern format cards. What other players think about these changes as I am attached with old cards.