@skypilot35.... I think seven years is indeed a long time to spend as a regional FO....but with the end of stagnation these days the regional airlines will be faced with the prospect of hiring very low time pilots who are eligible for upgrade withing less than two years.
Also....while seven years is a long time to spend as an FO at a regional airline making very low pay it's not a long time to spend as an FO in a 30-40 year airline career span. Such an FO should be just as competitive for a job at a major airline sitting right seat in a Boeing or Airbus as anybody. In fact I think they are better suited for that job than to sit left seat in a regional jet which requires a higher level of expertise and experience even though they may be qualified and capable....but still it is a better captain who has spent more time as a career first officer (at reasonable pay). After all, almost half of all professional airline pilots must be first officers so it follows that an average pilot would spend half their career as a first officer.
From a purely professional perspective, sitting in the left seat of a regional jet takes a lot more skill and experience than sitting in the right seat of any other airliner for any other airline...even heavies. My point is that it's a bad distribution of experience to take regional jet captains and transition them to right seat at a new "major" airline especially when they take a pay cut for several years just for the chance of higher salaries down the road. It's not a natural economic transition, it's a result of using regional airlines as a massive B scale for the major airlines.
Speaking from experience I can assure you that there is no mystical extra skills needed to work as a first officer on a heavy jet flying long haul than flying short haul in the right seat of a regional jet. In fact the opposite is probably true. In countries where the playing field is more level and seniority is not an issue first officers will often desire the short haul route so they can build the experience needed to become more proficient and companies may assign long haul heavy jets to the first officers who don't perform as well in training where their flying skills are less relevant.
As regional pilots you need to get over the mindset that your goal is to sit in the right seat of a mainline as a career goal and then just figure you will ride the seniority wave to the left seat.
As a regional jet pilot when you walk into the cockpit of a mainline jet for a jumpseat and the first officer acts politely smug and asks you if one day you would like to have his job you should politely say "no, I've already had your job...I hope to have his job" (pointing at the captain's seat).