On one hand, sure, the British took a lot of things from other places when their empire spanned the globe. And, it sucks for places that had their stuff taken that it is no longer where it was.
On the other hand the British Museum is probably one of the safest places in the world for these things. The museum cares about preservation, knows how to do it, and has the funds to do it. And, while there's undoubtedly corruption in the UK, there's a very low chance that any of these things is going to disappear out of the museum and into some powerful person's private collection.
Mohamed Salah is standing in front of a statue from Egypt, which was taken from Egypt to London. But, the British didn't manage to take the Buddhas of Bamiyan from Afghanistan to London, and what happened? The Taliban blew them up. The British also didn't fully loot Iraq when they controlled that territory, which meant that in the 2003 war the museum was looted but not by people who wanted treasures for a public museum. The poorer and less politically stable a country is, the greater the chances that their cultural treasures will be stolen or destroyed.
Despite the repression and corruption, Egypt is now probably stable enough that if any of these items were returned to Egypt, they would probably be well treated and put on display for Egyptians to see. The power of the military in Egypt and the level of corruption probably means a few small items would disappear from the museum, but the most important items would make it. But, is Egypt stable enough that the museum would be safe for another 20, 40, 80 years? I have my doubts. I do think London is probably safe for that long.
Maybe it's just me, but I think the number one priority should be preserving these things for the future. Displaying them for the public should be a lower priority. If there are items like scrolls or clothing that are too delicate to even display behind a glass case, they should be stored away. I know that's how they handle things at the Smithsonian, and I assume the British Museum is the same. Because of that, my bias is that the most important cultural items should be in the care of the richest museums in the world, even if it means that they're not in the places they came from.
