I think you can't choose between poker and roulette because everyone has their own tastes and everyone decides for themselves what suits them best. For example, my friend and I play roulette and poker very often, and we also place bets. Of course, like everywhere else, we do not always win, but often. I think you need an analytical mind and a bit of luck to win at gambling. By the way, roulette has a 5% advantage to the gambling house, which is also very important. I can recommend you one site ign88.co where we play with a friend and we really like it, you can use it if you need it.
I have more than 2 months playing poker on https://thegamereward.com/bingo-blitz/, and he never had problems with it. I know it is really difficult to make the thing what to play. Not only that, but I started playing different gambling games more than 5 years ago. Likewise, I also played roulette, and decided to try this one too. Now, I think this is the best for me. You have to try both of them and decided which one is the best for you, all this depends on preferences. I have a lot of friends that love poker, and we play together, but there are some of them, that will prefer something else.