>> Extending it without plugins, many of which are paid, is a nightmare.
Many of are free, and you can often build your own. You can easily extend it without plugins, but you're doing your future self a favor if you stuck your new features in one (so you can update themes etc easily in the future).
>> Adding custom fields is laborious, configuring post type display modes is a slog as well.
Hard disagree here. Whether you are using ACF for custom fields or post types, doing it manually takes more time but is not that difficult. Its typically a set of actions you wouldn't do often either.
Many of are free, and you can often build your own. You can easily extend it without plugins, but you're doing your future self a favor if you stuck your new features in one (so you can update themes etc easily in the future).
>> Adding custom fields is laborious, configuring post type display modes is a slog as well.
Hard disagree here. Whether you are using ACF for custom fields or post types, doing it manually takes more time but is not that difficult. Its typically a set of actions you wouldn't do often either.