It really depends on so many factors but I'll start by saying that it is not really feasible to carry all my gear on a trip, my backers don't have that much funds! Although I know some people count their photo gear in 'numbers of suitcases'.

I try to anticipate the trip and bring a flexible set that covers the needs I am likely to encounter. It may happen that I don't have the right lens or camera for a particular shot but it's not like I'm about to run out of pictures to take with whatever I have.

As a base, I start with 2 or 3 camera bodies and one wide-angle, one medium and one longer lens, plus one tripod. I rarely carry two longs, so either I go with a bright but shorter like my 50-135mm F2.8 or the longer 60-250mm F/4. The third camera is usually an ultra-compact for family vacations, or an ultra-zoom for other trips. That gives a lot of flexibility and backup in the event that a lens fails rather than a camera. Never happened to me so far, but I've seen people only shooting using a 300mm lens because their general purpose zoom failed, usually by falling of from a certain height.

I fill the rest such as prime lenses, a second tripod, etc based on specific needs that I can anticipate. I usually try to slip in one macro lens, but from experience it rarely gets used.

From there, most days I carry all ONE set around: One body, matching lenses and tripods. I avoid as much as possible to carry my primary and backup together. When going out even to dinner, I'll leave on set in the hotel and one comes with me. Who knows what might get robbed? The hotel or me first? If there is a safe big enough, the the hotel gear does in. Most time it is not. So I attach my hard suitcase using a special metal cable and lock to a permanent fixture of the hotel. Or, if I am using a soft one, like a backpack, then I put it in a metal mesh which is attached to a hotel fixture as well.

Nothing here is everything-proof but every bit we make it harder to be taken away reduces the chances of it disappearing.

Whether hotels are safe or not depends on so many factors. So you won't get a useful answer. I've been to places where people leave their laptops unattended in the lobby and nothing happens... and I've also seen police investigating items which disappeared from under the dining table while people were dining! In some restaurants, they give you twist ties so that you can attach your bag to the table or chair!