Re 1) AEs are still a neat base for more advanced and very useful architectures; visual semantic segmentation uses a similar architecture that adds 1x1 skip connections, LVAE/beta-VAE are useful for anomaly/fraud detection even today. AEs give us a pretty cool way to do customizable dimensionality reduction as well, so PCA/ICA/t-SNE/t-UMAP/etc. might not be needed in the best case.