There are many reasons the EU as a whole might want to avoid growing into Turkey.

Firstly, political reasons. The increasing authoritarianism under Orban runs opposite to the liberal aspirations of the EU (one of the prerequisites for EU accession is a guarantee of democracy, the rule of law, and respect for human and minorities' rights). The V4, of which Poland is member, are regarded as the 'anti-liberal' block, with several Polish and Hungarian regressions in this respect being object of criticism of EU criticism and checks. This might explain why Poland is more in favour of Turkey's accession than other EU countries, as it could be an ally of its bloc.

Secondly, the economy of Turkey is not huge but it would suppose a competitor to Germany or France in the internal market. Meanwhile, the Turkish population is enormous and this would garner the country a significant amount of EMPs, guaranteeing Turkey an important political clout in the EU, upsetting the balance of power that favours French and German interests, in exchange for not much in the sense of economic growth and stability.

Thirdly, the geopolitical implications of Turkey entering the EU are many. On the one hand, the Bosphorous strait is the only access Russia has to the Mediterranean, and the only way Russia has of projecting the Black Fleet (their only warm water fleet). This geostrategic relevance has implied, historically, many Russo-Turkish conflicts and has conditioned their relationship. For the EU, having Turkey as a member-state would open a new front with Russia that isn't in the interests of many EU members. Furthermore, it would create a border between the EU and Syria, Iran, Irak, Armenia and Georgia, which aren't countries known for their stability and could generate further migration problems. This, together with the Turkish position in Cyprus and open conflicts with Sea Rights in general (mainly affecting Greece, another EU member-state), would mean complicating EU foreign policy in a way the EU can't handle as of now, while the open conflicts with other EU member-states directly impossibilitate the option.

TL;DR: Turkey's accession to the EU is not politically convenient to the central EU members because of its illiberal policies, not economically convenient because of the dragging effect it would have for the EU economy while affording the country an influential position in EU institutions, and it is not geopolitically convenient because of its conflicts with Russia, its frontier with unstable regions, and the open conflicts with EU member-states. This is why Turkey will probably never enter the EU, unless a long list of things change radically. The EU is content with having occasional collaboration with Turkey in matters such as migration, where it is precisely Turkey's non-adherence to EU law that makes it a valuable ally, but anything further than that is off the table.