How bad off was the strategic situation of the Byzantines in Northwest Anatolia in the 1280s? Could the Northwestern coast of Anatolia have at least been held with more competent emperors? At the time of Michael VIIIs demise, the Byantines still had a very powerful army and a pretty large navy, although it was costing the Treasury a large amount of money, and the Byzantines had not lost any major amount of territory or important cities in Anatolia to the Turks, and the Byzantines have at least held or even slightly improved their position in the European part of the empire.
The situation wasn't good. Land had been gradually lost over the last century. As an example, the village of Sogut, not far from Nicaea, was captured by Ertugrul in 1231. The distance is a mere 51 miles, a single day's ride. It became the nucleus of the Ottoman beylik later in the 13th/14th century.
Just before he died, Michael VIII visited Anatolia and was shocked by the devastation, caused by invading Turkic tribes. Other factors to consider:
1. The Byzantines were bankrupt after decades of war, the cost of rebuilding Constantinople, the cost of funding the Sicilian Vespers, and Michael's mercenary troops.
2. The Turks were migrating into Byzantine territory because the Mongols had conquered their land
3. The Palaiologoi were usurpers who were unpopular in Anatolia
4. The Union of the Church with Rome was deeply unpopular
It may have been possible to salvage something, but it certainly wasn't an easy situation. Andronikos II failed utterly, but his failures are largely a result of trying to correct the problems caused by the previous ruler, Michael VIII.