They can do it by supplying softer compound tires. This will cause the tires in use to wear that much faster, and need to pit for a change. They show the scale of softness for the tires they are using each weekend, and there is usually a couple notches of softness to go. But that would make the hards, mediums, and softs, super-softs.
It isn't always as simple as just bringing a softer compound. The construction of the tire and actual makeup of the compound play a massive role.
It wasn't that many years ago that entire seasons were spent driving around at a reduced pace conserving the tires and never pushing because that was quicker overall compared to doing fast laps and needing to pit.
Unfortunately it seems Pirelli don't really have the goods in terms of being able to provide a tire that provides a pace benefit after a stop but still has the durability to allow a driver to push through a stint. I hate to bash a company or supplier, but really is the feeling I get.
Examples of how this plays out include the 2004 French Grand Prix, with Michael Schumacher winning on a maximum attack 4-stop strategy.
In IMSA a few years back, the difference between the Michelin tires on the GTLM cars compared to the Hankooks on the prototypes.
Similar could be seen when Super GT and DTM shared a technical rulebook, but different tires. The DTM cars ran a spec Hankook, whereas the Super GT cars ran an open tire that not only was faster, but also more durable, with some teams able to make a single set last a 300km race (the same length as a GP).
The reverse was also happened in this years Bathurst 1000, where softer rubber was used which pretty much killed the racing due to poor durability meaning everyone just cruised around.
TL;DR, lots more than just bring softer rubber, tires are an absurdly complex problem and probably involve a lot of black magic as well
