The simple answer is that you're not taking about the same countries. Gaza only borders Israel and Egypt. Neither of those took in much Syrian refugees.
Egypt did take in some Syrian refugees but way back in 2012 (145K according to UN), before there were a lot of political changes in Egypt. The number of Syrians in Egypt actually went down to 116K in 2016, according to Wikipedia. As for accepting refugees from Gaza...
At a time when there are increasing concerns about a potential mass Palestinian migration toward the Egyptian border with Gaza, Sisi emphasized that "there will be no compromise on Egypt’s national security under any circumstances, and the Egyptian people must be aware of the complexities of the situation and the magnitude of the threat.” [...]
He added that Egypt will not allow the termination of the Palestinian cause at the expense of other parties.
As for Israel, apparently it accepted zero Syrian refugees (ibid).
And to quote from a
related Q, there' not much appetite for more refugees even in Turkey these days:
President Recep Tayyip Erdoğan’s administration has forcibly deported hundreds of Syrian refugees since late 2022, while his primary challenger, Kemal Kılıçdaroğlu, has vowed to send all Syrian refugees back to their country of origin in under two years, regardless of circumstances in Syria.
Or in Europe for that matter, at least at its borders. Maybe Germany would be more accepting, but unless they plain airlift them, it's not even clear how they'd even get there.
And Germany hasn't done a lot explaining but
Germany on Wednesday [Nov 15] said that Israeli Finance Minister Bezalel Smotrich’s call for a “voluntary migration” of Palestinians in Gaza is “not acceptable.”
"We have noted these comments. They are not helpful. They are also not acceptable," deputy Foreign Ministry spokesman Christian Wagner told media representatives in Berlin.
FWTW, this is probably not the only reason but:
According to figures from the Federal Office for Migration and Refugees, Germany registered a 28% increase in asylum applications in 2022, with over 244,000. The top three sources of applicants were Syria, Afghanistan and Turkey; Ukrainians do not have to apply.
But the newcomers encounter a harsh reality: 12 out of 16 states in Germany currently do not have enough space to handle refugees, according to a local media report. The issue is particularly pressing in the cold winter months, amid a scramble to ensure that people have at least a makeshift roof over their heads.
And:
SEPTEMBER 20, 2023
German President Frank-Walter Steinmeier said the number of migrants coming to the country had pushed it to “breaking point,” as he called for a fairer European system of migrant distribution.
FWTW:
"Bulgaria last year received some 20,000 asylum applications – the highest number in a single year over 30 years of recorded statistics," Boris Cheshirkov from UNHCHR Bulgaria told InfoMigrants. The main countries of origin of asylum seekers were Syria, Afghanistan, and Morocco (Ukrainians are exempt from the asylum application process).
Proportionally with their (7 million) population, that's about the same per capita as applications in Germany, last year.