As long as it is not a big investment, it never hurts to have them "just in case"
The combination of excellent colors for the Commander format, a body with so many good abilities, and the free proliferate effect is tough to beat
Despite hovering in the $2.50 range for most of the last few years, Slowbro saw a huge uptick in late 2024 heading into 2025 when all Pokemon cards began surging to new heights
Those counters don't do much while the token has its front face up, but they do a great job of keeping the Phyrexian artifact creature alive once it transforms
However, there is another, more unique variety of ability, and this kind of ability is why a specific Charmeleon is often used in Charizard decks in the current format
In true precon fashion, these themes lead to rather sloppy deckbuilding since they don't interact particularly well