This question has hit me like a ton of bricks lately. With many new players streaming into the game at break-neck speed this has become the common issue for many of them to level up.
Though that is okay, that is a safeguard that was very wisely implemented several months ago to prevent abusive behavior and ill-gotten gains from player rewards with low level bots grabbing higher end rewards.
The collection score component in game has been wonderful and has definitely set the bar to a very solid standard making leveling up in the game incredibly difficult and no small feat.
But I think there could be an option explored in the collection power formula. Everything just the same as it is (or whatever the levels of the next upgrade for double quests of wildcard and modern formats) but have SPS staked as an additional factor.
This sends a great message to new players that "SPS is the gold standard of the game, so go ahead and stack it, stake it, and stay a while." While allowing players over time to earn these tokens and stake them, enabling them to have to rent less cards to add collection power (a gain to the player purely in opportunity cost) the player base will be allowed to possibly reap greater gains over time if they are here to stay.
A formula would have to weight collection power differently between simple burn value of cards and necessarily create a "peg value" similar to what The Splinterlands did with DEC, but it certainly could be done if it were a viable concept. For example, if one staked SPS token were worth 50 of the standard collection power unit, then the players lacking in collection power close to leveling would be much more inclined to stake.
Even a possible bonus schedule of percentage boost in collection power based on SPS staked might even be an option. Allowing the player to level up themselves might be a fun dynamic in an already highly dynamic game that is just getting started in its nuances in a player experience. Think if you're a new player and you get say a 1% collection power boost for staking 100 SPS tokens, then the next level to attain would be 500 SPS tokens for a 2.5% boost, and so on. Making that option 10 levels would be a fun option and further reward those that wish to stay and win long term.
Of course there are several other reasons to stake already, that is not the issue. But giving credit to the influx of the new players in the game as a bonus to earn more would be a phenomenal option in my humble opinion.