Faded by long-distance love interest. Did I do anything wrong?

I’ve been living in my head thinking about what went wrong with this woman I’ve fallen for. We first met back in mid-2018, connected briefly, then went back to our respective countries which are on opposite sides of the world. We stayed in touch and met once again at the end of the year when I travelled to her country. During the second half of 2019, we got in touch again and started text almost every day and have occasional scheduled calls. While we still lived far away, I felt there was a connection between us and the conversations have always been… natural, raw and personal. As we grew closer, I picked up the courage to do things that I hoped would show how I felt, such as sending her a gift on her birthday, which she seemed to love. I’ve been honest about how I thought she was special and amazing – although I never said “I like you”. Then, we met again in Christmas 2019 when I travelled to her place again. At this point, I started to really like her but was unsure of what would happen with the distance – and the fact that there’s no chance of us moving closer to each other in the next 2 years at least. We went out a few times and had the best time. I did what I thought would show how I felt – flowers, gifts with handwritten notes, picked up the tabs and planned the dates to her liking. By this point, it was clear that both of us really enjoyed each other’s company. She has always been receptive of my advances and said she had lovely time with me, even asked me to visit often. I was still hesitant to tell her outright I liked her, as I was still hoping there would come a day in which we’ll live in the same city together, and I’d stand a better chance then. I was trying to make an arrangement in which I would live closer to her for a few months mid-year and wanted to use the momentum to tell her then. Anyway, after returning home, we still texted. I did a couple more things to keep keep the “sparks”, e.g. sending flowers to her office, which she said she liked! However, several weeks in, things turned different. After she came back from a trip to visit her parents, her schedules had turned busy with work and other commitments, and she started responding less. I didn’t have any reason to believe that she didn’t want to speak with me – everything was going well just before that. I didn’t hear back for a couple of weeks, couldn’t call her. Finally managed to hear back. She said she’d been hectic so wasn’t able to text anymore. I was surprised so decided to tell her outright how I felt. She then said she just wanted to be friends and that she doesn’t want me to waste my effort/time. I’ve been replaying this to figure out if there was anything I could have done to save the situation. Do you think I did anything wrong?

No. That's the short answer! You did nothing wrong but the distance between you was too great to overcome. Sometimes, probably more often than not, people decide not to wait for a relationship when distance is an issue, even when that relationship could be something special. The chance of losing that relationship to have one right now is often a better option for some people. I'm only guessing but it's possible she has made that decision and may even have moved on. Lick your wounds then find someone closer to focus your energy on. It will be ok.