When I looked for this 11 years ago, tumblr was the only platform ticking these boxes. I just wanted to share a link to photos of what we are up to with family and friends without asking them to register at another platform, and only tumblr allowed that and did not look as if it would close shop within two years.
Looked again recently and it still seems to be the only platform filling that overall „niche“. Also it has a clean and good user interface, and is customizable to the point of changing the HTML. I hope they can save or otherwise sustain it.
Other social media attempts to constantly distract and emotionalize me to keep me hooked. Looking at a good art or photography Tumblr feels like relief now honestly.