The MLP universe has shrunk to fewer than 40 names (frommany more a decade ago) as tax-law changes and investor preference for simpler structures drove a wave of conversions to C-corporations (Magellan Midstream, Kinder Morgan, ONEOK-style structures). Remaining MLPs still issue Schedule K-1 tax forms, which complicates personal tax filing versus a normal 1099 - a real practical friction for retail investors. Leverage is rising at some names (MPLX at 3.7x after recent M&A) and distribution coverage, while currently solid, would compress in a sustained low-crude environment. MLP-wrapper ETFs like AMLP hold the entity-level C-corp tax structure themselves, which has historically caused them to trail the total return of owning the underlying MLPs directly (117% 5-yr return for AMLP vs 198%+ for MPLX and WES directly) - the ETF trades simplicity for a real cost.