Wood on the facade is NOT a STABLE substrate. There are different types of finishes for it - oil, glaze, varnish, enamel, paint. All of them, with some variations, are paint materials.
Oil, glaze, varnish – practically do not contain pigment and on such "transparent" after the formation of the film you can see the base. And therefore require a "beautiful" appearance, with prior preparation (sanding).
Enamel and paint are pigmented, so will cover the base. The base must be dry clean and firm. But the pigments will burn out.
Also, the material should be applied to an "unstable" substrate. This is good adhesion and the necessary elasticity. What's the point of all this? If you want to do the longest possible, you need the highest quality material. You can forget about the various DIY level stores. At the most you'll get what you can buy there, with a 5 year lifespan. Oils are ALL designed to last 5 years, after which the quality upgrade is even less. For wood, even good materials have a life span of 10 years +. It also depends on the operating conditions.
Oil – up to 5 years
Varnish – for an additional decorative effect with a shorter life span
Enamel – a thinner paint with increased durability. Also not very necessary for the facade elasticity.
Paint is the most technically suitable material. BUT it will cover the base, the pigment should not burn out quickly (depends on the color and quality)
Quality of lacquer and paint. Composition: 5 basic components
1) solvent (water, thinner)
Paints and varnishes Good / bad (cheap)
binder (still depends on its quality) a lot of approx. 40% / 15%
filler 20% / 40%
pigment 20% / 5%
solvent 15% / 37%
5% / 3% additives
Hardness; wet abrasion resistance; scratch resistance; good covering power. The formulation of each material is a closely guarded secret. And miracles do not happen that a cheap paint turns out to be a good one.