Let's be honest: yes it is, but it'll never get recognised for that because Pokemon came first and in the minds of many whoever does something first does it best and is the only thing that can/should be acknowledged for doing it, and Digimon has long been seen as a "clone" of Pokemon despite the fact that it was never acutally intended to be a competitor to Pokemon, it started life out as a series of Virtual Pets. It's an apples and oranges comparison that has grown in the minds of the masses as a direct like-for-like comparison due to coincidental similarities. Really, all the two actually share is that they both focus around children with monster companions and they both gained prominence in the 90s, there the similarities end. Completely. Watch the anime, play the video games, play the card game, and you'll realise just how completely different the two are.
Outside of the designs of the monsters themselves, I would say Digimon is superior in every other aspect to Pokemon. The games have an actual narrative to back up their substantial gameplay, which itself is generally better designed in terms of its systems and flexibility in approach to evolution and team building, and the anime is generally better for its character development and lack of excessive filler and general tedium - although this is a difficult thing to compare because Pokemon is a long-running franchise that has to reset at the start of every generation, and Digimon can start afresh with a new cast every 50 episodes or so. Going back to the monster designs...that's very much an apples and oranges comparison to me. Pokemon can't do complex designs without making a complete mess of them, whereas Digimon can, and some of its best monsters are the ones with excessive detail. Although it definitely takes this too far with X Digimon; you can barely tell what the damn things are sometimes. But Pokemon's most memorable designs, the simpler ones, are absolutely fantastic. Whilst I don't like regional forms, I also think they're a lot better than the straight-up palette swaps that Digimon has. I mean, the whole BlackAgumon line is great and all, but...god, there are so many, and they're so unnecessary and forgettable.
Digimon also proves the point that a franchise can acknowledge that its original fanbase has grown older and cater to them and younger fans WITHOUT losing its identity, something Pokemon has always struggled with. It's a franchise that has matured with its audience, but still carries that appeal to a younger generation of fans. I've seen all kinds of excuses made for Pokemon games retaining their simplicity, but...well, Digimon just destroys all of those excuses by virtue of its very presence. It's just bad game design, plain and simple.
But I look at the two as completely different, and I like them for different reasons. I like Pokemon because it takes me back to my childhood and because it never changes; there is comfort in familarity and I know exactly what I'm getting with the franchise, I don't expect something different. I like Digimon because its matured with me, and it has themes and games that appeal to me more now that I'm adult and can appreciate things I would have hated as a child. Digimon is more in-line with my current tastes in video games and anime; it provides a more substantial and fresh experience. Comparing it to Pokemon wouldn't be fair, because the two fulfil different functions in my life. But between the two, looking at how they've aged, I would say Digimon is substantially better.