Having an older condo in Thailand with what appears to be poor levels of maintenance is not an uncommon issue. What the reasons this may be I will leave for owners to consider for themselves, all I can comment upon is another area we used to live that had the same issue and in most cases has overcome it.
Chiang Mai had numerous older condos and many were run down and poorly maintained, this continued from year to year. So what changed things? High foreign ownership with motivated owners wanting the building sorted out. What they discovered was that there were plenty of Thai owners that wanted the same, knew what was required to resolve but didn’t want the conflict. They were however happy to deliver their votes at the AGM (Annual General Meeting) to remove the existing Committee and replace the management structure for those with a plan. I sat in one of those fiery AGMs and watched it happen, things then improved.
Those buildings now come across looking vastly better, the maintenance is being done and what was broken has been repaired, owners have also seen their property values increase substantially with what is now an attractive place to buy. Some buildings here have the same problem, it is resolvable but requires the numbers and probably high and motivated foreign ownership. Regardless it will occur at some stage, beach locations are limited, here too will eventually boom. Personally we like the laid back life just as it is.