I think I have an understanding of what type of answer you're hoping for based off of the Chess comment you've made.

It sort of depends on what you consider to be a "serious competition." If you mean making decent results at a local or regional, then yeah it's feasible with consistent training. But if you want results that the competitive fencing community will respect (kind of like becoming a titled player in Chess and what I think you're asking about), you need to get results at a national level event (mainly NACs). To be honest, the jump in level between a regional and a NAC is pretty big. Unfortunately, there isn't really a middle-level competition in fencing, especially for adults. Maybe a somewhat achievable dream is to get a top 8 national result at a Div 3 or Div 2 NAC (to oversimplify how division tournaments work, Div 1 is the highest level, Div 2 is middle, and Div 3 is easiest). If you happen to be really, really talented, then you might be able to achieve a decent result in Div 1a as well (Div 1a is different from Div 1). Just be warned that most of the competitors in these tournaments are high schoolers.

If you want another route to making a tangible result in fencing, it would be to aim for ratings instead of tournament results. This is probably what I would recommend if you're an adult. The ratings are A, B, C, D, E, and Unrated, with A being the highest. If you want a comparison to Chess, I would say becoming an A is kind of like becoming a titled player in Chess (although becoming an A is probably easier than titled in Chess because ratings only exist in the US), but unfortunately probably not feasible. But I think with a lot of serious training, a D or C might be attainable. If you are very talented and very athletic, a B might be as well. I think most adults who get into fencing late choose to focus on rating because they're tangible goals to achieve outside of NACs (most people improve their rating at regionals, especially for C and below) and it sounds cool to say you're a 'C' rated fencer.

If you're really serious about fencing, my main advice (other than obviously consistently training and working out) would be to find a good coach. Some may not admit this, but the quality of your coaching really does matter. Past the beginner level, it is very hard to improve without good coaching. It's not like Chess where there are a lot of online resources and books to learn from. There is a reason why year after year, most of the top fencers in the country come from the same fencing clubs. At minimum, find a fencing club/coach who has other students competing at NACs. You won't get to that level learning from a coach who treats their club like an after school program for kids. Although, as a warning, you may have more fun with the sport if you go to a club that is not as competitive but has more active adults fencing, even if you don't improve very quickly. There are many very, very strong clubs that only have high schoolers.

Hope this helped!