The lack of a Battle Tower and any other facility, otherwise a staple even in obviously rushed games like SwSh and XY, could mean that they're saving a Frontier for DLC to compensate and also as a big marketing point.
I don’t think either of those games were rushed. The first game on each console is usually the most pathetic and feature lacking game because they spend most of the dev time and budget on building the engine. The follow up games get to skip that step and have many more months to iron things out.
Red/Blue and D/P look beyond basic compared to Gold/Silver and Black & White for example.