Apple Inc.’s stock had a very good run in 2023, but it is starting 2024 with looming issues that make it look expensive for investors.To begin, Apple AAPL, +2.02% has morphed into a slow-growth company, failing to increase year-over-year revenue in each of its past four reported quarters. The company is heavily reliant on its iPhone business, but innovation on the device has stagnated, making consumers less likely to upgrade their devices in a rockier economic climate. All the while, Apple shares carry a hi ...