I agree with you, football teams that get promoted to the 1st division Should have a sufficient budget to sign high level players and coaches, in fact in the PL we realized that Whoever pushes from the middle of the season and gets a good score has a good chance of winning the PL , more so in this season where City went down like a ravine, now things are getting better, what I like about the PL is the Physical level of demand, it's the best.
Getting promoted brings benefits like increased TV revenue, ticket sales, and better sponsorships, but that doesn't mean these teams can suddenly afford top talent. High quality players and coaches often avoid newly promoted teams due to limited trophy chances and wage demands that might be out of their budget. Signing players is one thing and paying their wages is another. These teams might have to settle for players nearing retirement, where wages are more negotiable because it's tough for promoted teams to attract and retain top talent.
But, not all have the financial ability as you mentioned. some of them who are promoted to the top league just hope to stay in the premier league as long as possible even though they can't get the title or unable to sign top level player and coach. At the first, it's hard to get sponsors if they don't have star players, they need several seasons to get high value sponsors if they are able to stay in the top league.
Their performance over the years will determine if they will attract good players but even at that I doubt if they'd attract good players. they can only get players that are about to leave a big club looking for a new team and probably as a free agent.